The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain functio...The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with emotions.Specifically, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal mice.After knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was obviously mitigated. Additionally, administration of an excitatory amino acid transporter 2 inhibitor in the basolateral amygdala yielded a notable reduction in anxiety level among mice subjected to stress. These results suggest that basolateral amygdala astrocytic excitatory amino acid transporter 2 plays a role in in the regulation of unpredictable chronic mild stress-induced anxiety-like behavior by impacting the activity of local glutamatergic neurons, and targeting excitatory amino acid transporter 2 in the basolateral amygdala holds therapeutic promise for addressing anxiety disorders.展开更多
Bromodomain and plant homeodomain(PHD)finger containing protein 1(Brpf1)is an activator and scaffold protein of a multiunit complex that includes other components involving lysine acetyltransferase(KAT)6A/6B/7.Brpf1,K...Bromodomain and plant homeodomain(PHD)finger containing protein 1(Brpf1)is an activator and scaffold protein of a multiunit complex that includes other components involving lysine acetyltransferase(KAT)6A/6B/7.Brpf1,KAT6A,and KAT6B mutations were identified as the causal genes of neurodevelopmental disorders leading to intellectual disability.Our previous work revealed strong and specific expression of Brpf1 in both the postnatal and adult forebrain,especially the hippocampus,which has essential roles in learning and memory.Here,we hypothesized that Brpf1 plays critical roles in the function of forebrain excitatory neurons,and that its deficiency leads to learning and memory deficits.To test this,we knocked out Brpf1 in forebrain excitatory neurons using CaMKIIa-Cre.We found that Brpf1 deficiency reduced the frequency of miniature excitatory postsynaptic currents and downregulated the expression of genes Pcdhgb1,Slc16a7,Robo3,and Rho,which are related to neural development,synapse function,and memory,thereby damaging spatial and fear memory in mice.These findings help explain the mechanisms of intellectual impairment in patients with BRPF1 mutation.展开更多
Excitation and inhibition are at the core of brain function and malfunction.To sustain the activity of neuronal networks over time and space,glutamatergic excitation is balanced by GABAergic inhibition.The equipoise o...Excitation and inhibition are at the core of brain function and malfunction.To sustain the activity of neuronal networks over time and space,glutamatergic excitation is balanced by GABAergic inhibition.The equipoise of excitation and inhibition,known as the excitation/inhibition(E/I)balance,is crucial for proper brain function.The E/I balance is highly dynamic and shifts across different brain states:wakefulness primarily augments excitatory activity,while sleep promotes a decrease in excitation and an increase in inhibition(Bridi et al.,2020).Neuronal activity during various brain states is primarily regulated by neurotransmitters(Schiemann et al.,2015),alongside non-synaptic mechanisms that operate on a slower timescale.The non-synaptic mechanisms are many,with the ionic composition of the extracellular space playing a significant role;altering extracellular ion concentrations affects sleep,arousal,electroencephalogram patterns,and behavioral states(Ding et al.,2016).展开更多
In this study, nine high-lysine maize kernels and two kernels of common maize hybrid were used as experiment materials, and quantitative determination of lysine contents in high-lysine maize kernels and common maize k...In this study, nine high-lysine maize kernels and two kernels of common maize hybrid were used as experiment materials, and quantitative determination of lysine contents in high-lysine maize kernels and common maize kernels was carried out using Hitachi L-8900 Automatic Amino-acid Analyzer, to know the effect of the Analyzer in distinguishing the lysine contents between common maize kernels and high-lysine maize kernels. The results showed that the lysine contents of high-lysine maize kernels were among 0.34%-0.42%, while of common maize kernels were a- mong 0.24%-0.25%, and the difference was significant. Compared with other tradi- tional methods, this method is rapid, simple, sensitive, highly reproductive and needs fewer maize kernels, thus it is applicable in maize breeding.展开更多
Acute ischemic stroke is a clinical emergency and a condition with high morbidity,mortality,and disability.Accurate predictive,diagnostic,and prognostic biomarkers and effective therapeutic targets for acute ischemic ...Acute ischemic stroke is a clinical emergency and a condition with high morbidity,mortality,and disability.Accurate predictive,diagnostic,and prognostic biomarkers and effective therapeutic targets for acute ischemic stroke remain undetermined.With innovations in high-throughput gene sequencing analysis,many aberrantly expressed non-coding RNAs(ncRNAs)in the brain and peripheral blood after acute ischemic stroke have been found in clinical samples and experimental models.Differentially expressed ncRNAs in the post-stroke brain were demonstrated to play vital roles in pathological processes,leading to neuroprotection or deterioration,thus ncRNAs can serve as therapeutic targets in acute ischemic stroke.Moreover,distinctly expressed ncRNAs in the peripheral blood can be used as biomarkers for acute ischemic stroke prediction,diagnosis,and prognosis.In particular,ncRNAs in peripheral immune cells were recently shown to be involved in the peripheral and brain immune response after acute ischemic stroke.In this review,we consolidate the latest progress of research into the roles of ncRNAs(microRNAs,long ncRNAs,and circular RNAs)in the pathological processes of acute ischemic stroke–induced brain damage,as well as the potential of these ncRNAs to act as biomarkers for acute ischemic stroke prediction,diagnosis,and prognosis.Findings from this review will provide novel ideas for the clinical application of ncRNAs in acute ischemic stroke.展开更多
BZ]Dendro dendritic and dendro somatic projections are common between spinal motoneurons. We attempted to clarify whether there are functional connections through these projections. Methods. Motoneurons were antidromi...BZ]Dendro dendritic and dendro somatic projections are common between spinal motoneurons. We attempted to clarify whether there are functional connections through these projections. Methods. Motoneurons were antidromically stimulated by the muscle nerve and recorded intracellularly to examine the direct interaction between them, after the related dorsal roots had been cut. Results. Excitatory connections, demonstrated by depolarizing potentials in response to muscle nerve stimulation, were found between motoneurons innervating the same muscle or synergistic muscles, but never between motoneurons innervating antagonistic muscles. These potentials were finely graded in response to a series of increasing stimuli and resistant to high frequency (50Hz) stimulation. Conclusions.These results indicate that excitatory connections, with certain specificity of spatial and temporal distribution, occur in the spinal motoneurons. It is also suggested that electrical coupling should be involved in these connections and this mechanism should improve the excitability of the motoneurons in the same column.展开更多
Selective cerebral deep hypothermia and blood flow occlusion can enhance brain tolerance to ischemia and hypoxia and reduce cardiopulmonary complications in monkeys. Excitotoxicity induced by the release of a large am...Selective cerebral deep hypothermia and blood flow occlusion can enhance brain tolerance to ischemia and hypoxia and reduce cardiopulmonary complications in monkeys. Excitotoxicity induced by the release of a large amount of excitatory amino acids after cerebral ischemia is the major mechanism underlying ischemic brain injury and nerve cell death. In the present study, we used selective cerebral deep hypothermia and blood flow occlusion to block the bilateral common carotid arteries and/or bilateral vertebral arteries in rhesus monkey, followed by reperfusion using Ringer's solution at 4~C. Microdialysis and transmission electron microscope results showed that selective cerebral deep hypothermia and blood flow occlusion inhibited the release of glutamic acid into the extracellular fluid in the brain frontal lobe and relieved pathological injury in terms of the ultrastructure of brain tissues after severe cerebral ischemia. These findings indicate that cerebral deep hypothermia and blood flow occlusion can inhibit cytotoxic effects and attenuate ischemic/ hypoxic brain injury through decreasing the release of excitatory amino acids, such as glutamic acid.展开更多
The polymerase acidic protein is an important family of proteins from influenza A virus, which is classified as many different subtypes or spe-cies. Thus, an important question is if these classifications are numerica...The polymerase acidic protein is an important family of proteins from influenza A virus, which is classified as many different subtypes or spe-cies. Thus, an important question is if these classifications are numerically distinguishable with respect to the polymerase acidic protein. The amino-acid pair predictability was used to transfer 2432 polymerase acidic proteins into 2432 scalar data. The one-way ANOVA found these polymerase acidic proteins distinguish-able in terms of subtypes and species. However, the large residuals in ANOVA suggested a pos-sible large intra-subtype/species variation. Therefore, the inter- and intra-subtype/species variations were studied using the model II ANOVA. The results showed that the in-tra-subtype/species variations accounted most of variation, which was 100% in total for both inter- and intra- subtype/species variations. Our analysis threw lights on the issue of how to de-termine a wide variety of patterns of antigenic variation across space and time, and within and between subtypes as well as hosts.展开更多
BACKGROUND: Under normal conditions, excitatory amino acids are dynamically balanced with inhibitory amino acids. Excitatory amino acids have been implicated in perinatal brain injury. OBJECTIVE: To investigate diff...BACKGROUND: Under normal conditions, excitatory amino acids are dynamically balanced with inhibitory amino acids. Excitatory amino acids have been implicated in perinatal brain injury. OBJECTIVE: To investigate differences in the levels of the excitatory amino acids glutamic acid and aspartic acid, and the inhibitory amino acid gamma-aminobutyric acid (GABA) in the cerebrospinal fluid (CSF) of children with spastic cerebral palsy or athetotic cerebral palsy. DESIGN, TIME AND SETTING: Case-control exploratory observation of neurotransmitter in patients. The experiment was performed in the Pediatrics Department of the Second Affiliated Hospital of Changsha Medical College, the Cerebral Palsy Center of Xiangtan Affiliated Hospital of South China University and the Pediatrics Department of Xiangya Hospital, between February 2006 and May 2007. PARTICIPANTS: We selected 27 children with cerebral palsy, including 13 with spastic cerebral palsy and 14 with athetotic cerebral palsy. We selected 10 patients who were not affected by any neurological disease as controls. METHODS: Two mL blood-free CSF was harvested between the third and fourth lumbar vertebrae of each patient after anesthesia, and stored at -70℃. One mL CSF was mixed with 10 mg sulfosalicylic acid and placed in ice-bath for 10 minutes, then centrifuged 2 000 g for 10 minutes. The supernatant was collected for amino acid quantitation. MAIN OUTCOME MEASURES: The concentrations of glutamic acid, aspartic acid and GABA in the CSF were determined by high-performance liquid chromatography and fluorometric method. The correlation of glutamic acid, aspartic acid and GABA levels with muscular tension in children with cerebral palsy was analyzed using linear dependence. RESULTS: The concentration of GABA was significantly lower in both spastic cerebral palsy and athetotic cerebral palsy patients than in the control group (P 〈 0.01). Glutamic acid and aspartic acid were significantly higher in both cerebral palsy groups than in the control group (P 〈 0.05-0.01). The concentration of GABA was significantly decreased in spastic cerebral palsy patients compared with the athetotic cerebral palsy group (P 〈 0.05). Muscular tension was positively correlated with the concentration of glutamic acid in spastic cerebral palsy patients (P 〈 0.05) but there was no significant correlation between aspartic acid or GABA and muscular tension (P 〉 0.05). CONCLUSION: Spastic cerebral palsy and athetotic cerebral palsy patients exhibit an imbalance of excitatory amino acids and inhibitory amino acids in their CSF: an increase in glutamic acid and aspartic acid, and a decrease in GABA. Amino acid levels are different in the CSF in varied types of cerebral palsy.展开更多
To elucidate the correlation between excitatory amino acids (EAA) and spinal cord injury, we investigat-ed the dynamic changes in excitatory amino acids, aspartate (Asp) and glutamate (Gin ) contents in cerebrospinalf...To elucidate the correlation between excitatory amino acids (EAA) and spinal cord injury, we investigat-ed the dynamic changes in excitatory amino acids, aspartate (Asp) and glutamate (Gin ) contents in cerebrospinalfluid (CSF) of 26 patients with acute spinal cord injury by amino acids autoanalyzer. The results showed that con-tent of glutanlate and aspartate was renlarkably elevated in 24 h after trauma and was related to the seventy of injury. The more severe the spinal cord injured, the more remarkable the content of Asp and Gin in CSF increased.The more pronounced the content of EAA in CSF increased, the worse the patient’s prognosis was. Content of EAA in CSF after spinal cord injury may be an indicator to judge injury extent and prognosis. and provide further support for a potential pathophysiological role of EAA in spinal cord injury.展开更多
Sprague-Dawley rats were subjected to traumatic spinal cord injury using Allen's method. Regional concentrations of excitatory amino acid (EAA) were assessed by high-performance liquid chromatography, and regional...Sprague-Dawley rats were subjected to traumatic spinal cord injury using Allen's method. Regional concentrations of excitatory amino acid (EAA) were assessed by high-performance liquid chromatography, and regional water and ion content were measured by the atomic absorption spectrophotometry at various times after intrathecal administration of different dosage of 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP),a specific antagonist of N-methyl-D-aspartame (NMDA) receptor,to rat at 48 h posttrauma.The results showed that concentrations of glutamate and aspartate were elevated rapidly at 15, 30 min and were correlated positively with the severity of injury. In the injured segment there was a significant increase in water, Na+ ,Ca++ content and a decrease in K+ , Mg++. Whereas in CPP treated groups they had a statistically significant return, which was related to the dosage and time of administration. This effect of CPP suggests that ion and water content were related to overactivation of NMDA receptor. Excessive high levels of EAA may be involved in secondary tissue damage following spinal cord injury.展开更多
To investigate the protective mechanism of nerve growth factor (NGF) on spinal cord injury (SCI), surgical spinal cord injury in Wistar rats was performed by a 10 g2.5 cm impact on the posterior spinal cord at T8 leve...To investigate the protective mechanism of nerve growth factor (NGF) on spinal cord injury (SCI), surgical spinal cord injury in Wistar rats was performed by a 10 g2.5 cm impact on the posterior spinal cord at T8 level, and a thin plastic tube was placed in subarachoid space below the injury level for perfusion of solution. To the experimental animals were given 60 g (20 l liquid) NGF, purified from bovine seminal plasma, at the moment of injury and 1,2,3,4,8,12,24 h after injury. An equal volume of normal saline was given to rats of the control group at the same time. In the expermental group, the injured spinal cord tissue was taken following treatment. The contents of the excitatory amino acids (Glu, Asp) were determined by high performance liquid chromatography (HPLC). Excitatory amino acid contents in the injured spinal cord were significantly increased at 10 min and 8 h after the injury as compared with those in the control group. However, The peak values of the excitatory amino acid contents in NGF group were obviously lowered. NGF might protect spinal cord against injury in vivo. One of the possible mechanisms is that NGF prohibits neurotoxicity of the exitatory amino acids.展开更多
Objective To detect the effect of excitatory ammo add (EAA) in the secondary damage following spinal cord injury (SCI). Methods Glutamate (Glu) and Aspartate (Asp) on the injury site (T8) were studied using a rat SCI ...Objective To detect the effect of excitatory ammo add (EAA) in the secondary damage following spinal cord injury (SCI). Methods Glutamate (Glu) and Aspartate (Asp) on the injury site (T8) were studied using a rat SCI model induced by Allen's weight drop method (10g×2. 5cm). The result suggested that Asp and Glu were significantly increased in 10 mm. Results Glu was significantly decreased from 2 h to 24 h,while Asp was a tittle reduced in 2 h,and slightly rose in 4 h as compared with Control Group. Though elevated in 8 h,it dropped again in 24h as compared with Control Group. Conclusion The result indicates that the rise of EAA following SCI could be the cause of the secondary spinal cord damage.展开更多
In traditional viewpoint,excitatory modulation always promotes neural firing activities.On contrary,the negative responses of complex bursting behaviors to excitatory self-feedback mediated by autapse with time delay ...In traditional viewpoint,excitatory modulation always promotes neural firing activities.On contrary,the negative responses of complex bursting behaviors to excitatory self-feedback mediated by autapse with time delay are acquired in the present paper.Two representative bursting patterns which are identified respectively to be“Fold/Big Homoclinic”bursting and“Circle/Fold cycle”bursting with bifurcations are studied.For both burstings,excitatory modulation can induce less spikes per burst for suitable time delay and strength of the self-feedback/autapse,because the modulation can change the initial or termination phases of the burst.For the former bursting composed of quiescent state and burst,the mean firing frequency exhibits increase,due to that the quiescent state becomes much shorter than the burst.However,for the latter bursting pattern with more complex behavior which is depolarization block lying between burst and quiescent state,the firing frequency manifests decrease in a wide range of time delay and strength,because the duration of both depolarization block and quiescent state becomes long.Therefore,the decrease degree of spike number per burst is larger than that of the bursting period,which is the cause for the decrease of firing frequency.Such reduced bursting activity is explained with the relations between the bifurcation points of the fast subsystem and the bursting trajectory.The present paper provides novel examples of paradoxical phenomenon that the excitatory effect induces negative responses,which presents possible novel modulation measures and potential functions of excitatory self-feedback/autapse to reduce bursting activities.展开更多
Aim Prenatal stress (PS) can lead to abnormal behavior of offspring and increase the incidence of mental illness. Previous researches have shown that levels of glutamate and its receptor expression are closely relat...Aim Prenatal stress (PS) can lead to abnormal behavior of offspring and increase the incidence of mental illness. Previous researches have shown that levels of glutamate and its receptor expression are closely relat- ed to the occurrence of this phenomenon. Furthermore, recent study has demonstrated that the expression levels of excitatory amino acid transporters 2 (EAAT2) in different brain regions of 1 month PS offspring rats have changed. Methods The SD pregnant rats were used restraint stress to imitate PS from gestation 14 -~ 19 days. Offspring rats were weaned 21 days after birth. The expression of EAAT2 of hippocampus was observed by Western blot. Results The expression of EAAT2 of 1 month PS offspring rats was significantly decreased in comparison to control group. However, the expression of EAAT2 of 2 month PS offspring rats was significantly increased in comparison to 1 month PS offspring rats. Conclusion These phenomena have illustrated that the expression of EAAT2 of PS off- spring rats could show time dependence or reversibility. The expression of EAAT2 may play an important role in the development of mental illness of offspring rats influenced by PS.展开更多
Different from the common delayed synchronization(DS)in which response appears after stimulation,anticipated synchronization(AS)in unidirectionally coupled neurons denotes a counterintuitive phenomenon in which respon...Different from the common delayed synchronization(DS)in which response appears after stimulation,anticipated synchronization(AS)in unidirectionally coupled neurons denotes a counterintuitive phenomenon in which response of the receiver neuron appears before stimulation of the sender neuron,showing an interesting function of brain to anticipate the future.The dynamical mechanism for the AS remains unclear due to complex dynamics of inhibitory and excitatory modulations.In this article,the paradoxical roles of excitatory synapse and inhibitory autapse in the formation of AS are acquired.Firstly,in addition to the common roles such that inhibitory modulation delays and excitatory modulation advances spike,paradoxical roles of excitatory stimulation to delay spike via type-II phase response and of inhibitory autapse to advance spike are obtained in suitable parameter regions,extending the dynamics and functions of the excitatory and inhibitory modulations.Secondly,AS is related to the paradoxical roles of the excitatory and inhibitory modulations,presenting deep understandings to the AS.Inhibitory autapse induces spike of the receiver neuron advanced to appear before that of the sender neuron at first,and then excitatory synapse plays a delay role to prevent the spike further advanced,resulting in the AS as the advance and delay effects realize a dynamic balance.Lastly,inhibitory autapse with strong advance,middle advance,and weak advance and delay effects induce phase drift(spike of the receiver neuron advances continuously),AS,and DS,respectively,presenting comprehensive relationships between AS and other behaviors.The results present potential measures to modulate AS related to brain function.展开更多
The mutation pattern in protein is a very important feature and is studied through various approaches including the study on mutation pattern in domains where amino acids are converted into numbers from letters. In th...The mutation pattern in protein is a very important feature and is studied through various approaches including the study on mutation pattern in domains where amino acids are converted into numbers from letters. In this study, we converted the amino acids in human adrenoleukodystrophy protein with its 128 missense mutations into random domain using the amino-acid pair predictability, and then we studied their mutation patterns. The results show 1) the mutations are more likely to target the amino-acid pairs whose actual frequency is larger than their predicted one, 2) the mutations are more likely to form the amino-acid pairs whose actual frequency is smaller than their predicted frequency, 3) mutations are more likely to occur at unpredictable amino-acid pairs, and 4) mutations have the trend to narrow the difference between predicted and actual frequencies of amino-acid pairs.展开更多
Objective: To observe the effects of morphine on the excitatory postsynaptic currents (EPSCs) and miniature EPSCs (mEPSCs) in rat supraoptic nucleus (SON) neurons and to explore its synaptic mechanism. Methods: Using ...Objective: To observe the effects of morphine on the excitatory postsynaptic currents (EPSCs) and miniature EPSCs (mEPSCs) in rat supraoptic nucleus (SON) neurons and to explore its synaptic mechanism. Methods: Using whole-cell voltage-clamp recording technique in the brain slices, the EPSCS and mEPSCs of rat SON neurons were recorded, respectively. Results: Morphine (20μmol/L) decreased the frequency of EPSCs and mEPSCs (by 65% for EPSCS and by 45% for mEPSCs), and reduced the amplitude of EPSCs by 44% in all SON neurons, but the amplitude distribution of mEPSCs was not affected. Conclusion: Morphine inhibits the excitatory transmissions via presynaptic mechanisms in SON neurons from rat brain slices.展开更多
A formalin-treated polyvinyl-alcohol (PVF) sponge is convenient as a scaffold because its configuration is easily modified. However, coating the sponge with an adhesive chemical agent is necessary to attach bone marro...A formalin-treated polyvinyl-alcohol (PVF) sponge is convenient as a scaffold because its configuration is easily modified. However, coating the sponge with an adhesive chemical agent is necessary to attach bone marrow cells (BMCs) to the sponge structure. Moreover, it was considered that a hybrid scaffold composed of a sponge and enveloped cylindrical porous hydroxyapatite (HA) would be convenient. In this study, the effect of leucine (Leu) coating on a PVF sponge was examined for osteogenesis on an HA/PVF hybrid scaffold by rat BMCs (rBMCs). In an in vivo assessment, the sponge immersed in Leu solution (10 mg/ml) was inserted into the hollow center of cylindrical HA. The sponge received 1.5 × 106 rBMCs obtained from male Fischer 344 rats. The hybrid scaffolds were then implanted subcutaneously of syngeneic rats for 6 weeks. In vitro assessment of Leu to hard tissue formation with coating on the well or addition in rBMC culture medium was also performed in a 6-well plate for 2 weeks. In vivo examinations showed the excellent effect of Leu coating on PVF sponge. Leu-coated PVF sponge in the scaffolds showed marked new bone formation in the pores by histological examination. Leu-coated PVF sponge showed a high quantity of osteocalcine (OC). HA might prevent the release of rBMCs from PVF as a barrier. In in vitro examinations, the quantity of OC in rBMC culture with and without the addition of Leu in culture medium showed no significant difference. However, addition of Leu showed significant ALP activity level in culture medium. Leu coating in culture plate wells showed no influence on the quantity of OC. It was concluded from the results that Leu might prevent the emigration of rBMCs to the outside of the scaffold and promote the differentiation of cells to osteoblasts in the scaffold.展开更多
BACKGROUND: Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is o...BACKGROUND: Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is one of the important transmitters for alcohol tolerance in central nervous system. OBJECTIVE: To observe the changes of excitatory amino acids in hippocampal dentate gyrus in rats with long-term alcohol drinking after withdrawal under consciousness, and investigate the therapeutic effect of topiramate on alcohol withdrawal. DESIGN : A randomized control animal experiment SETTING : Department of Neurology, Affiliated Hospital of Yanbian University MATERIALS: Thirty male Wistar rats of 4 months old, weighing 300-350 g, were purchased from the Experimental Animal Department, Medical College of Yanbian University. Topiramate was produced by Swish Cilag Company, and the batch number was 02CS063. METHODS: The experiments were carried out in the Department of Physiology, Medical College of Yanbian University from August 2005 to February 2006. ① The rats were divided randomly into three groups: control group (n=10), alcohol group (n=10) and topiramate-treated group (n=10). Rats in the alcohol group and topiramate-treated group were given intragastric perfusion of 500 g/L alcohol (10 mL/kg), once a day for 4 weeks successively, and then those in the topiramate-treated group were treated with 80 mg/kg topiramate at 24 hours after the last perfusion of alcohol, once a day for 3 days successively. Rats in the control group were intragastricly given isovolume saline. ② The withdrawal symptoms were assessed at 6, 30, 48 and 72 hours after the last perfusion of alcohol by using the withdrawal rating scale set by Erden et al, which had four observational indexes of stereotyped behaviors, agitation, tail stiffness and abnormal posture, each index was scored by 5 points, the higher the score, the more obvious the symptoms. ③ The contents of aspartic acid and glutamic acid in hippocampal dentate gyrus were detected with microdialysis technique and high-performance liquid chromatograpy (HPLC) respectively at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the three groups. MAIN OUTCOME MEASURES : ① Scoring results of alcohol withdrawal symptoms; ② Changes of the contents of aspartic acid and glutamic acid in hippocampal dentate gyrus at the alcohol withdrawal symptoms, and the effects of topiramate. RESULTS: Seven rats were excluded due to inaccurate localization and natural death, and 23 rats were involved in the analysis of results. ①In the alcohol group, the scores of alcohol withdrawal symptoms at 30 and 48 hours after the last perfusion of alcohol were obviously higher than those in the control group (10.50±0.96, 14.17±1.25; 3.50±0.92, 3.16±0,31; P 〈 0.01). In the topiramate-treated group, the scores at 30 hours after the last perfusion of alcohol (6.06±0.82, 3.50±0.92, P 〈 0.05), and the withdrawal scores at 48 and 72 hours were close to those in the control group (4.57±0.58, 3.30±0.71; 3.16±0.31, 3.66±0.67; P 〉 0.05).② Changes of the contents of glutamic acid in hippocampal dentate gyrus: In the alcohol group, the content of glutamic acid at 48 hours after the last perfusion of alcohol was significantly increased as compared with that at 6 hours [(143.32±11.42)%, (99.12±0.69)%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [(78.50±16.40)%, (99.12±0.69)%; P 〉 0.05]. The contents of glutamic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [(100.30±0.37)%, (118.91±10.40)%, (99.55±12.81)%, (99.08±11.42)%; P 〉 0.05], The content of glutamic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group (P 〈 0.05), and those at 30 and 72 hours were close (P 〉 0.05). ③ Changes of the contents of aspartic acid in hippocampal dentate gyrus: In the alcohol group, the contents of aspartic acid at 30 and 48 hours after the last perfusion of alcohol were significantly increased as compared with that at 6 hours [(126.60±8.67)%, (129.17±10.40)%, (99.25±0.87)%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [(89.87±9.93)%, (99.25±0.87)%; P 〉 0.05]. The contents of aspartic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [(100.27±0.32)%, (120.81 ±12.63)%, (98.91±7.83)%, (85.92±8.07)%; P 〉 0.05]. The content of aspartic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group (P 〈 0.05), and those at 30 and 72 hours were close (P 〉 0.05). CONCLUSION: ① The occurrences of alcohol withdrawal symptoms are correlated with the increased contents of excitatory amino acids in hippocampal dentate gyrus in rats. ② Topiramate can alleviate the alcohol withdrawal symptoms, which may be correlated with the decreased contents of excitatory amino acids in hippocampal dentate gyrus in rats.展开更多
基金supported by the National Natural Science Foundation of China,Nos.32371070 (to JT),31761163005 (to JT),32100824 (to QX)the Shenzhen Science and Technology Program,Nos.RCBS20210609104606024 (to QX),JCY20210324101813035 (to DL)+4 种基金the Guangdong Provincial Key S&T Program,No.2018B030336001 (to JT)the Key Basic Research Program of Shenzhen Science and Technology Innovation Commission,Nos.JCYJ20200109115405930 (to JT),JCYJ20220818101615033 (to DL),JCYJ20210324115811031 (to QX),JCYJ20200109150717745 (to QX)Shenzhen Key Laboratory of Neuroimmunomodulation for Neurological Diseases,No.ZDSYS20220304163558001 (to JT)Guangdong Provincial Key Laboratory of Brain Connectome and Behavior,No.2023B1212060055 (to JT)the China Postdoctoral Science Foundation,No.2021M693298 (to QX)。
文摘The conventional perception of astrocytes as mere supportive cells within the brain has recently been called into question by empirical evidence, which has revealed their active involvement in regulating brain function and encoding behaviors associated with emotions.Specifically, astrocytes in the basolateral amygdala have been found to play a role in the modulation of anxiety-like behaviors triggered by chronic stress. Nevertheless, the precise molecular mechanisms by which basolateral amygdala astrocytes regulate chronic stress–induced anxiety-like behaviors remain to be fully elucidated. In this study, we found that in a mouse model of anxiety triggered by unpredictable chronic mild stress, the expression of excitatory amino acid transporter 2 was upregulated in the basolateral amygdala. Interestingly, our findings indicate that the targeted knockdown of excitatory amino acid transporter 2 specifically within the basolateral amygdala astrocytes was able to rescue the anxiety-like behavior in mice subjected to stress. Furthermore, we found that the overexpression of excitatory amino acid transporter 2 in the basolateral amygdala, whether achieved through intracranial administration of excitatory amino acid transporter 2agonists or through injection of excitatory amino acid transporter 2-overexpressing viruses with GfaABC1D promoters, evoked anxiety-like behavior in mice. Our single-nucleus RNA sequencing analysis further confirmed that chronic stress induced an upregulation of excitatory amino acid transporter 2 specifically in astrocytes in the basolateral amygdala. Moreover, through in vivo calcium signal recordings, we found that the frequency of calcium activity in the basolateral amygdala of mice subjected to chronic stress was higher compared with normal mice.After knocking down the expression of excitatory amino acid transporter 2 in the basolateral amygdala, the frequency of calcium activity was not significantly increased, and anxiety-like behavior was obviously mitigated. Additionally, administration of an excitatory amino acid transporter 2 inhibitor in the basolateral amygdala yielded a notable reduction in anxiety level among mice subjected to stress. These results suggest that basolateral amygdala astrocytic excitatory amino acid transporter 2 plays a role in in the regulation of unpredictable chronic mild stress-induced anxiety-like behavior by impacting the activity of local glutamatergic neurons, and targeting excitatory amino acid transporter 2 in the basolateral amygdala holds therapeutic promise for addressing anxiety disorders.
基金supported by the National Natural Science Foundation of China,No. 81771228Shanghai Association of Science and Technology,Nos. 22WZ2501700 and 23WZ2504500 (all to LY)
文摘Bromodomain and plant homeodomain(PHD)finger containing protein 1(Brpf1)is an activator and scaffold protein of a multiunit complex that includes other components involving lysine acetyltransferase(KAT)6A/6B/7.Brpf1,KAT6A,and KAT6B mutations were identified as the causal genes of neurodevelopmental disorders leading to intellectual disability.Our previous work revealed strong and specific expression of Brpf1 in both the postnatal and adult forebrain,especially the hippocampus,which has essential roles in learning and memory.Here,we hypothesized that Brpf1 plays critical roles in the function of forebrain excitatory neurons,and that its deficiency leads to learning and memory deficits.To test this,we knocked out Brpf1 in forebrain excitatory neurons using CaMKIIa-Cre.We found that Brpf1 deficiency reduced the frequency of miniature excitatory postsynaptic currents and downregulated the expression of genes Pcdhgb1,Slc16a7,Robo3,and Rho,which are related to neural development,synapse function,and memory,thereby damaging spatial and fear memory in mice.These findings help explain the mechanisms of intellectual impairment in patients with BRPF1 mutation.
文摘Excitation and inhibition are at the core of brain function and malfunction.To sustain the activity of neuronal networks over time and space,glutamatergic excitation is balanced by GABAergic inhibition.The equipoise of excitation and inhibition,known as the excitation/inhibition(E/I)balance,is crucial for proper brain function.The E/I balance is highly dynamic and shifts across different brain states:wakefulness primarily augments excitatory activity,while sleep promotes a decrease in excitation and an increase in inhibition(Bridi et al.,2020).Neuronal activity during various brain states is primarily regulated by neurotransmitters(Schiemann et al.,2015),alongside non-synaptic mechanisms that operate on a slower timescale.The non-synaptic mechanisms are many,with the ionic composition of the extracellular space playing a significant role;altering extracellular ion concentrations affects sleep,arousal,electroencephalogram patterns,and behavioral states(Ding et al.,2016).
基金Supported by Henan Major Scientific and Technological Project(121100110300)Outstanding Youth Project of Henan Academy of Agricultural Sciences(2013YQ006)~~
文摘In this study, nine high-lysine maize kernels and two kernels of common maize hybrid were used as experiment materials, and quantitative determination of lysine contents in high-lysine maize kernels and common maize kernels was carried out using Hitachi L-8900 Automatic Amino-acid Analyzer, to know the effect of the Analyzer in distinguishing the lysine contents between common maize kernels and high-lysine maize kernels. The results showed that the lysine contents of high-lysine maize kernels were among 0.34%-0.42%, while of common maize kernels were a- mong 0.24%-0.25%, and the difference was significant. Compared with other tradi- tional methods, this method is rapid, simple, sensitive, highly reproductive and needs fewer maize kernels, thus it is applicable in maize breeding.
基金supported by the National Natural Science Foundation of China,Nos.82301486(to SL)and 82071325(to FY)Medjaden Academy&Research Foundation for Young Scientists,No.MJR202310040(to SL)+2 种基金Nanjing Medical University Science and Technique Development,No.NMUB20220060(to SL)Medical Scientific Research Project of Jiangsu Commission of Health,No.ZDA2020019(to JZ)Health China Buchang Zhiyuan Public Welfare Project for Heart and Brain Health,No.HIGHER202102(to QD).
文摘Acute ischemic stroke is a clinical emergency and a condition with high morbidity,mortality,and disability.Accurate predictive,diagnostic,and prognostic biomarkers and effective therapeutic targets for acute ischemic stroke remain undetermined.With innovations in high-throughput gene sequencing analysis,many aberrantly expressed non-coding RNAs(ncRNAs)in the brain and peripheral blood after acute ischemic stroke have been found in clinical samples and experimental models.Differentially expressed ncRNAs in the post-stroke brain were demonstrated to play vital roles in pathological processes,leading to neuroprotection or deterioration,thus ncRNAs can serve as therapeutic targets in acute ischemic stroke.Moreover,distinctly expressed ncRNAs in the peripheral blood can be used as biomarkers for acute ischemic stroke prediction,diagnosis,and prognosis.In particular,ncRNAs in peripheral immune cells were recently shown to be involved in the peripheral and brain immune response after acute ischemic stroke.In this review,we consolidate the latest progress of research into the roles of ncRNAs(microRNAs,long ncRNAs,and circular RNAs)in the pathological processes of acute ischemic stroke–induced brain damage,as well as the potential of these ncRNAs to act as biomarkers for acute ischemic stroke prediction,diagnosis,and prognosis.Findings from this review will provide novel ideas for the clinical application of ncRNAs in acute ischemic stroke.
基金This study was supported by the grant from ClimbingProgram of Chinese Committee of Science
文摘BZ]Dendro dendritic and dendro somatic projections are common between spinal motoneurons. We attempted to clarify whether there are functional connections through these projections. Methods. Motoneurons were antidromically stimulated by the muscle nerve and recorded intracellularly to examine the direct interaction between them, after the related dorsal roots had been cut. Results. Excitatory connections, demonstrated by depolarizing potentials in response to muscle nerve stimulation, were found between motoneurons innervating the same muscle or synergistic muscles, but never between motoneurons innervating antagonistic muscles. These potentials were finely graded in response to a series of increasing stimuli and resistant to high frequency (50Hz) stimulation. Conclusions.These results indicate that excitatory connections, with certain specificity of spatial and temporal distribution, occur in the spinal motoneurons. It is also suggested that electrical coupling should be involved in these connections and this mechanism should improve the excitability of the motoneurons in the same column.
基金supported by the National Natural Science Foundation of China, No. 30960398the 47th Post-doctoral Scientific Foundation of China, No. 20100470376the Natural Science Foundation of Yunnan Province, No.2009CD178
文摘Selective cerebral deep hypothermia and blood flow occlusion can enhance brain tolerance to ischemia and hypoxia and reduce cardiopulmonary complications in monkeys. Excitotoxicity induced by the release of a large amount of excitatory amino acids after cerebral ischemia is the major mechanism underlying ischemic brain injury and nerve cell death. In the present study, we used selective cerebral deep hypothermia and blood flow occlusion to block the bilateral common carotid arteries and/or bilateral vertebral arteries in rhesus monkey, followed by reperfusion using Ringer's solution at 4~C. Microdialysis and transmission electron microscope results showed that selective cerebral deep hypothermia and blood flow occlusion inhibited the release of glutamic acid into the extracellular fluid in the brain frontal lobe and relieved pathological injury in terms of the ultrastructure of brain tissues after severe cerebral ischemia. These findings indicate that cerebral deep hypothermia and blood flow occlusion can inhibit cytotoxic effects and attenuate ischemic/ hypoxic brain injury through decreasing the release of excitatory amino acids, such as glutamic acid.
文摘The polymerase acidic protein is an important family of proteins from influenza A virus, which is classified as many different subtypes or spe-cies. Thus, an important question is if these classifications are numerically distinguishable with respect to the polymerase acidic protein. The amino-acid pair predictability was used to transfer 2432 polymerase acidic proteins into 2432 scalar data. The one-way ANOVA found these polymerase acidic proteins distinguish-able in terms of subtypes and species. However, the large residuals in ANOVA suggested a pos-sible large intra-subtype/species variation. Therefore, the inter- and intra-subtype/species variations were studied using the model II ANOVA. The results showed that the in-tra-subtype/species variations accounted most of variation, which was 100% in total for both inter- and intra- subtype/species variations. Our analysis threw lights on the issue of how to de-termine a wide variety of patterns of antigenic variation across space and time, and within and between subtypes as well as hosts.
基金a grant from Health Department of Hunan Province,No.B2006-204
文摘BACKGROUND: Under normal conditions, excitatory amino acids are dynamically balanced with inhibitory amino acids. Excitatory amino acids have been implicated in perinatal brain injury. OBJECTIVE: To investigate differences in the levels of the excitatory amino acids glutamic acid and aspartic acid, and the inhibitory amino acid gamma-aminobutyric acid (GABA) in the cerebrospinal fluid (CSF) of children with spastic cerebral palsy or athetotic cerebral palsy. DESIGN, TIME AND SETTING: Case-control exploratory observation of neurotransmitter in patients. The experiment was performed in the Pediatrics Department of the Second Affiliated Hospital of Changsha Medical College, the Cerebral Palsy Center of Xiangtan Affiliated Hospital of South China University and the Pediatrics Department of Xiangya Hospital, between February 2006 and May 2007. PARTICIPANTS: We selected 27 children with cerebral palsy, including 13 with spastic cerebral palsy and 14 with athetotic cerebral palsy. We selected 10 patients who were not affected by any neurological disease as controls. METHODS: Two mL blood-free CSF was harvested between the third and fourth lumbar vertebrae of each patient after anesthesia, and stored at -70℃. One mL CSF was mixed with 10 mg sulfosalicylic acid and placed in ice-bath for 10 minutes, then centrifuged 2 000 g for 10 minutes. The supernatant was collected for amino acid quantitation. MAIN OUTCOME MEASURES: The concentrations of glutamic acid, aspartic acid and GABA in the CSF were determined by high-performance liquid chromatography and fluorometric method. The correlation of glutamic acid, aspartic acid and GABA levels with muscular tension in children with cerebral palsy was analyzed using linear dependence. RESULTS: The concentration of GABA was significantly lower in both spastic cerebral palsy and athetotic cerebral palsy patients than in the control group (P 〈 0.01). Glutamic acid and aspartic acid were significantly higher in both cerebral palsy groups than in the control group (P 〈 0.05-0.01). The concentration of GABA was significantly decreased in spastic cerebral palsy patients compared with the athetotic cerebral palsy group (P 〈 0.05). Muscular tension was positively correlated with the concentration of glutamic acid in spastic cerebral palsy patients (P 〈 0.05) but there was no significant correlation between aspartic acid or GABA and muscular tension (P 〉 0.05). CONCLUSION: Spastic cerebral palsy and athetotic cerebral palsy patients exhibit an imbalance of excitatory amino acids and inhibitory amino acids in their CSF: an increase in glutamic acid and aspartic acid, and a decrease in GABA. Amino acid levels are different in the CSF in varied types of cerebral palsy.
文摘To elucidate the correlation between excitatory amino acids (EAA) and spinal cord injury, we investigat-ed the dynamic changes in excitatory amino acids, aspartate (Asp) and glutamate (Gin ) contents in cerebrospinalfluid (CSF) of 26 patients with acute spinal cord injury by amino acids autoanalyzer. The results showed that con-tent of glutanlate and aspartate was renlarkably elevated in 24 h after trauma and was related to the seventy of injury. The more severe the spinal cord injured, the more remarkable the content of Asp and Gin in CSF increased.The more pronounced the content of EAA in CSF increased, the worse the patient’s prognosis was. Content of EAA in CSF after spinal cord injury may be an indicator to judge injury extent and prognosis. and provide further support for a potential pathophysiological role of EAA in spinal cord injury.
文摘Sprague-Dawley rats were subjected to traumatic spinal cord injury using Allen's method. Regional concentrations of excitatory amino acid (EAA) were assessed by high-performance liquid chromatography, and regional water and ion content were measured by the atomic absorption spectrophotometry at various times after intrathecal administration of different dosage of 3-(2-carboxypiperazin-4-yl)-propyl-1-phosphonic acid (CPP),a specific antagonist of N-methyl-D-aspartame (NMDA) receptor,to rat at 48 h posttrauma.The results showed that concentrations of glutamate and aspartate were elevated rapidly at 15, 30 min and were correlated positively with the severity of injury. In the injured segment there was a significant increase in water, Na+ ,Ca++ content and a decrease in K+ , Mg++. Whereas in CPP treated groups they had a statistically significant return, which was related to the dosage and time of administration. This effect of CPP suggests that ion and water content were related to overactivation of NMDA receptor. Excessive high levels of EAA may be involved in secondary tissue damage following spinal cord injury.
文摘To investigate the protective mechanism of nerve growth factor (NGF) on spinal cord injury (SCI), surgical spinal cord injury in Wistar rats was performed by a 10 g2.5 cm impact on the posterior spinal cord at T8 level, and a thin plastic tube was placed in subarachoid space below the injury level for perfusion of solution. To the experimental animals were given 60 g (20 l liquid) NGF, purified from bovine seminal plasma, at the moment of injury and 1,2,3,4,8,12,24 h after injury. An equal volume of normal saline was given to rats of the control group at the same time. In the expermental group, the injured spinal cord tissue was taken following treatment. The contents of the excitatory amino acids (Glu, Asp) were determined by high performance liquid chromatography (HPLC). Excitatory amino acid contents in the injured spinal cord were significantly increased at 10 min and 8 h after the injury as compared with those in the control group. However, The peak values of the excitatory amino acid contents in NGF group were obviously lowered. NGF might protect spinal cord against injury in vivo. One of the possible mechanisms is that NGF prohibits neurotoxicity of the exitatory amino acids.
文摘Objective To detect the effect of excitatory ammo add (EAA) in the secondary damage following spinal cord injury (SCI). Methods Glutamate (Glu) and Aspartate (Asp) on the injury site (T8) were studied using a rat SCI model induced by Allen's weight drop method (10g×2. 5cm). The result suggested that Asp and Glu were significantly increased in 10 mm. Results Glu was significantly decreased from 2 h to 24 h,while Asp was a tittle reduced in 2 h,and slightly rose in 4 h as compared with Control Group. Though elevated in 8 h,it dropped again in 24h as compared with Control Group. Conclusion The result indicates that the rise of EAA following SCI could be the cause of the secondary spinal cord damage.
基金the National Natural Science Foundation of China(Grant Nos.11872276 and 11762001)the Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region,China(Grant No.NJYT-20-A09).
文摘In traditional viewpoint,excitatory modulation always promotes neural firing activities.On contrary,the negative responses of complex bursting behaviors to excitatory self-feedback mediated by autapse with time delay are acquired in the present paper.Two representative bursting patterns which are identified respectively to be“Fold/Big Homoclinic”bursting and“Circle/Fold cycle”bursting with bifurcations are studied.For both burstings,excitatory modulation can induce less spikes per burst for suitable time delay and strength of the self-feedback/autapse,because the modulation can change the initial or termination phases of the burst.For the former bursting composed of quiescent state and burst,the mean firing frequency exhibits increase,due to that the quiescent state becomes much shorter than the burst.However,for the latter bursting pattern with more complex behavior which is depolarization block lying between burst and quiescent state,the firing frequency manifests decrease in a wide range of time delay and strength,because the duration of both depolarization block and quiescent state becomes long.Therefore,the decrease degree of spike number per burst is larger than that of the bursting period,which is the cause for the decrease of firing frequency.Such reduced bursting activity is explained with the relations between the bifurcation points of the fast subsystem and the bursting trajectory.The present paper provides novel examples of paradoxical phenomenon that the excitatory effect induces negative responses,which presents possible novel modulation measures and potential functions of excitatory self-feedback/autapse to reduce bursting activities.
文摘Aim Prenatal stress (PS) can lead to abnormal behavior of offspring and increase the incidence of mental illness. Previous researches have shown that levels of glutamate and its receptor expression are closely relat- ed to the occurrence of this phenomenon. Furthermore, recent study has demonstrated that the expression levels of excitatory amino acid transporters 2 (EAAT2) in different brain regions of 1 month PS offspring rats have changed. Methods The SD pregnant rats were used restraint stress to imitate PS from gestation 14 -~ 19 days. Offspring rats were weaned 21 days after birth. The expression of EAAT2 of hippocampus was observed by Western blot. Results The expression of EAAT2 of 1 month PS offspring rats was significantly decreased in comparison to control group. However, the expression of EAAT2 of 2 month PS offspring rats was significantly increased in comparison to 1 month PS offspring rats. Conclusion These phenomena have illustrated that the expression of EAAT2 of PS off- spring rats could show time dependence or reversibility. The expression of EAAT2 may play an important role in the development of mental illness of offspring rats influenced by PS.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.12072236,12162002,and11802086)the Young Talents of Science and Technology in Universities of Inner Mongolia Autonomous Region(Grant No.NJYT-20-A09)the Program for Excellent Young Talents in Colleges and Universities of Anhui Province of China(Grant No.gxyq ZD2020077)。
文摘Different from the common delayed synchronization(DS)in which response appears after stimulation,anticipated synchronization(AS)in unidirectionally coupled neurons denotes a counterintuitive phenomenon in which response of the receiver neuron appears before stimulation of the sender neuron,showing an interesting function of brain to anticipate the future.The dynamical mechanism for the AS remains unclear due to complex dynamics of inhibitory and excitatory modulations.In this article,the paradoxical roles of excitatory synapse and inhibitory autapse in the formation of AS are acquired.Firstly,in addition to the common roles such that inhibitory modulation delays and excitatory modulation advances spike,paradoxical roles of excitatory stimulation to delay spike via type-II phase response and of inhibitory autapse to advance spike are obtained in suitable parameter regions,extending the dynamics and functions of the excitatory and inhibitory modulations.Secondly,AS is related to the paradoxical roles of the excitatory and inhibitory modulations,presenting deep understandings to the AS.Inhibitory autapse induces spike of the receiver neuron advanced to appear before that of the sender neuron at first,and then excitatory synapse plays a delay role to prevent the spike further advanced,resulting in the AS as the advance and delay effects realize a dynamic balance.Lastly,inhibitory autapse with strong advance,middle advance,and weak advance and delay effects induce phase drift(spike of the receiver neuron advances continuously),AS,and DS,respectively,presenting comprehensive relationships between AS and other behaviors.The results present potential measures to modulate AS related to brain function.
文摘The mutation pattern in protein is a very important feature and is studied through various approaches including the study on mutation pattern in domains where amino acids are converted into numbers from letters. In this study, we converted the amino acids in human adrenoleukodystrophy protein with its 128 missense mutations into random domain using the amino-acid pair predictability, and then we studied their mutation patterns. The results show 1) the mutations are more likely to target the amino-acid pairs whose actual frequency is larger than their predicted one, 2) the mutations are more likely to form the amino-acid pairs whose actual frequency is smaller than their predicted frequency, 3) mutations are more likely to occur at unpredictable amino-acid pairs, and 4) mutations have the trend to narrow the difference between predicted and actual frequencies of amino-acid pairs.
文摘Objective: To observe the effects of morphine on the excitatory postsynaptic currents (EPSCs) and miniature EPSCs (mEPSCs) in rat supraoptic nucleus (SON) neurons and to explore its synaptic mechanism. Methods: Using whole-cell voltage-clamp recording technique in the brain slices, the EPSCS and mEPSCs of rat SON neurons were recorded, respectively. Results: Morphine (20μmol/L) decreased the frequency of EPSCs and mEPSCs (by 65% for EPSCS and by 45% for mEPSCs), and reduced the amplitude of EPSCs by 44% in all SON neurons, but the amplitude distribution of mEPSCs was not affected. Conclusion: Morphine inhibits the excitatory transmissions via presynaptic mechanisms in SON neurons from rat brain slices.
文摘A formalin-treated polyvinyl-alcohol (PVF) sponge is convenient as a scaffold because its configuration is easily modified. However, coating the sponge with an adhesive chemical agent is necessary to attach bone marrow cells (BMCs) to the sponge structure. Moreover, it was considered that a hybrid scaffold composed of a sponge and enveloped cylindrical porous hydroxyapatite (HA) would be convenient. In this study, the effect of leucine (Leu) coating on a PVF sponge was examined for osteogenesis on an HA/PVF hybrid scaffold by rat BMCs (rBMCs). In an in vivo assessment, the sponge immersed in Leu solution (10 mg/ml) was inserted into the hollow center of cylindrical HA. The sponge received 1.5 × 106 rBMCs obtained from male Fischer 344 rats. The hybrid scaffolds were then implanted subcutaneously of syngeneic rats for 6 weeks. In vitro assessment of Leu to hard tissue formation with coating on the well or addition in rBMC culture medium was also performed in a 6-well plate for 2 weeks. In vivo examinations showed the excellent effect of Leu coating on PVF sponge. Leu-coated PVF sponge in the scaffolds showed marked new bone formation in the pores by histological examination. Leu-coated PVF sponge showed a high quantity of osteocalcine (OC). HA might prevent the release of rBMCs from PVF as a barrier. In in vitro examinations, the quantity of OC in rBMC culture with and without the addition of Leu in culture medium showed no significant difference. However, addition of Leu showed significant ALP activity level in culture medium. Leu coating in culture plate wells showed no influence on the quantity of OC. It was concluded from the results that Leu might prevent the emigration of rBMCs to the outside of the scaffold and promote the differentiation of cells to osteoblasts in the scaffold.
文摘BACKGROUND: Many researches have indicated that the imbalances of various amino acid transmitters and neurotransmitters in brain are involved in the formation of alcohol withdrawal, especially that glutamic acid is one of the important transmitters for alcohol tolerance in central nervous system. OBJECTIVE: To observe the changes of excitatory amino acids in hippocampal dentate gyrus in rats with long-term alcohol drinking after withdrawal under consciousness, and investigate the therapeutic effect of topiramate on alcohol withdrawal. DESIGN : A randomized control animal experiment SETTING : Department of Neurology, Affiliated Hospital of Yanbian University MATERIALS: Thirty male Wistar rats of 4 months old, weighing 300-350 g, were purchased from the Experimental Animal Department, Medical College of Yanbian University. Topiramate was produced by Swish Cilag Company, and the batch number was 02CS063. METHODS: The experiments were carried out in the Department of Physiology, Medical College of Yanbian University from August 2005 to February 2006. ① The rats were divided randomly into three groups: control group (n=10), alcohol group (n=10) and topiramate-treated group (n=10). Rats in the alcohol group and topiramate-treated group were given intragastric perfusion of 500 g/L alcohol (10 mL/kg), once a day for 4 weeks successively, and then those in the topiramate-treated group were treated with 80 mg/kg topiramate at 24 hours after the last perfusion of alcohol, once a day for 3 days successively. Rats in the control group were intragastricly given isovolume saline. ② The withdrawal symptoms were assessed at 6, 30, 48 and 72 hours after the last perfusion of alcohol by using the withdrawal rating scale set by Erden et al, which had four observational indexes of stereotyped behaviors, agitation, tail stiffness and abnormal posture, each index was scored by 5 points, the higher the score, the more obvious the symptoms. ③ The contents of aspartic acid and glutamic acid in hippocampal dentate gyrus were detected with microdialysis technique and high-performance liquid chromatograpy (HPLC) respectively at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the three groups. MAIN OUTCOME MEASURES : ① Scoring results of alcohol withdrawal symptoms; ② Changes of the contents of aspartic acid and glutamic acid in hippocampal dentate gyrus at the alcohol withdrawal symptoms, and the effects of topiramate. RESULTS: Seven rats were excluded due to inaccurate localization and natural death, and 23 rats were involved in the analysis of results. ①In the alcohol group, the scores of alcohol withdrawal symptoms at 30 and 48 hours after the last perfusion of alcohol were obviously higher than those in the control group (10.50±0.96, 14.17±1.25; 3.50±0.92, 3.16±0,31; P 〈 0.01). In the topiramate-treated group, the scores at 30 hours after the last perfusion of alcohol (6.06±0.82, 3.50±0.92, P 〈 0.05), and the withdrawal scores at 48 and 72 hours were close to those in the control group (4.57±0.58, 3.30±0.71; 3.16±0.31, 3.66±0.67; P 〉 0.05).② Changes of the contents of glutamic acid in hippocampal dentate gyrus: In the alcohol group, the content of glutamic acid at 48 hours after the last perfusion of alcohol was significantly increased as compared with that at 6 hours [(143.32±11.42)%, (99.12±0.69)%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [(78.50±16.40)%, (99.12±0.69)%; P 〉 0.05]. The contents of glutamic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [(100.30±0.37)%, (118.91±10.40)%, (99.55±12.81)%, (99.08±11.42)%; P 〉 0.05], The content of glutamic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group (P 〈 0.05), and those at 30 and 72 hours were close (P 〉 0.05). ③ Changes of the contents of aspartic acid in hippocampal dentate gyrus: In the alcohol group, the contents of aspartic acid at 30 and 48 hours after the last perfusion of alcohol were significantly increased as compared with that at 6 hours [(126.60±8.67)%, (129.17±10.40)%, (99.25±0.87)%; P 〈 0.05], and that at 72 hours was close to that at 6 hours [(89.87±9.93)%, (99.25±0.87)%; P 〉 0.05]. The contents of aspartic acid had no obvious differences at 6, 30, 48 and 72 hours after the last perfusion of alcohol in the topiramate-treated group [(100.27±0.32)%, (120.81 ±12.63)%, (98.91±7.83)%, (85.92±8.07)%; P 〉 0.05]. The content of aspartic acid at 48 hours after the last perfusion of alcohol in the topiramate-treated group was obviously lower than that in the alcohol group (P 〈 0.05), and those at 30 and 72 hours were close (P 〉 0.05). CONCLUSION: ① The occurrences of alcohol withdrawal symptoms are correlated with the increased contents of excitatory amino acids in hippocampal dentate gyrus in rats. ② Topiramate can alleviate the alcohol withdrawal symptoms, which may be correlated with the decreased contents of excitatory amino acids in hippocampal dentate gyrus in rats.