Long-term potentiation(LTP) of C-fiber evoked field potentials in spinal dorsal horn is first reported in 1995.Since then,the mechanisms underlying the long-lasting enhancement in synaptic transmission between primary...Long-term potentiation(LTP) of C-fiber evoked field potentials in spinal dorsal horn is first reported in 1995.Since then,the mechanisms underlying the long-lasting enhancement in synaptic transmission between primary afferent C-fibers and neurons in spinal dorsal horn have been investigated by different laboratories.In this article,the related data were summarized and discussed.展开更多
BACKGROUND: Long-term potentiation of cornu dorsale medullae spinalis field potential in adult rats has already been reported; however, there is lack of correlated researches on naenonate, infant and adult rats which...BACKGROUND: Long-term potentiation of cornu dorsale medullae spinalis field potential in adult rats has already been reported; however, there is lack of correlated researches on naenonate, infant and adult rats which have different responses to pain conduction information.OBJECTIVE: To observe the various effects of electric stimulation at sciatic nerve on long-term potentiation of evoked field potential at superficial layer of cornu dorsale medullae spinalis of rats at various developmental phases and analyze manifestations of pain conduction information at superficial layers ( Ⅰ - Ⅱ)of cornu dorsale medullae spinalis in immature rats.DESIGN: Grouping controlled study.SETTING: Department of Physiology, Medical College of Wuhan University.MATERIALS: The experiment was carried out in the Laboratory of Physiology (provincial laboratory),Medical College of Wuhan University from March 2006 to May 2007. A total of 27 healthy male Sprague-Dawley (SD) rats, 17- 90 days old, SPF grade, weighing 41 -200 g, were provided by Experimental Animal Center, Medical College of Wuhan University.METHODS: Based on their birthdays, rats were divided into naenonate group (17 - 20 days old, weighing 41-52 g, n =10), infant group (35 - 50 days old, weighing 87 - 125 g, n =10) and adult group (60 - 90 days old, weighing 180 -200 g, n =7). Left sciatic nerve was separated and stimulated with single square wave (15 V, 0.5 ms). Meanwhile, evoked field potential was recorded at superficial layers of lateral T13 - L1 cornu dorsale medullae spinalis and then stimulated with high-frequent and high-intensive tetanizing current (30 -40 V, 0.5 ms, 100 Hz, 1s per bundle, 10s in bundle interval) four times. After the operation, onset of long-term potentiation was observed; meanwhile, amplitude changes and latency of field potential were analyzed.MAIN OUTCOME MEASURES: Amplitude and latency changes of field potential at superficial layers of cornu dorsale medullae spinalis of rats in the three groups.RESULTS: A total of 27 accepted rats were involved in the final analysis. ① Amplitude changes: Electric stimulation at sciatic nerve with high-frequent and high-intensive tetanizing current could induce evoked field potential at superficial layers (Ⅰ-Ⅱ ) of cornu dorsale medullae spinalis in the three groups.Long-term potentiation in the naenonate group manifested that amplitude of A-kind never fiber was raised and there was significant difference (P〈0.05). In addition, average amplitude was increased and there was obviously significant difference (P〈0.01). Long-term potentiation in the infant group manifested that amplitude of C-kind never fiber was raised and there was significant difference (P〈0.01); while, long-term potentiation in the adult group manifested that amplitude of C-kind never fiber was raised and there was significant difference (P〈0.01). Otherwise, latencies in the three groups were all shortened. ② Latency changes: Average latency of A-kind nerve fiber in the naenonate group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of C-kind nerve fiber was low and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation (P〉0.05). Average latency of C-kind nerve fiber in the infant group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of A-kind nerve fiber was stable and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation (P〉0.05). Average latency of C-kind nerve fiber in the adult group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of A-kind nerve fiber was stable and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation.CONCLUSION: Evoked field potential at superficial layer of comu dorsale medullae spinalis can be recorded through electric stimulation at sciatic nerve. Single stimulation and tetanizing electric stimulation can cause different characteristics of evoked field potential in rats at various developmental phases.Superficial layer of cornu dorsale medullae spinalis of naenonate rats is mainly caused by A-kind nerve fiber which participants in pain conduction and formation of pain sensitivity; however, that of infant and adult rats mainly depends on C-kind nerve fiber.展开更多
In Japan, the shortage of personnel is a problem in long-term care nursing and rehabilitative care prevention. Nevertheless, Japan has taken measures to compensate for these shortages by promoting medical and nursing ...In Japan, the shortage of personnel is a problem in long-term care nursing and rehabilitative care prevention. Nevertheless, Japan has taken measures to compensate for these shortages by promoting medical and nursing care activities using robotic technologies, and employing human resources from overseas. The purpose of this study was to determine potential legal issues and subsequent implications for care during prevention gymnastic exercises for the elderly using Pepper in long-term health facilities. The application program of Care-Prevention Gymnastics Exercises for Pepper (Pepper with CPGE) was made by the Xing Company Japan. Currently, care workers become intermediaries for the safe use of Pepper with CPGE. However, it was realized that some legal issues may arise if Pepper with CPGE alone will carry out these preventive care programs for the elderly without the presence of care workers as intermediaries. In this situation, using Pepper with CPGE alone to conduct care prevention gymnastics will require safety measures to prevent these possible practice issues and anticipate implications for care. In this regard, determining detailed target levels of rehabilitation exercise demands and environmental setting safety become essential factors. The use of humanoid robots in healthcare is expected to influence more practice protocols in contemporary and futurist rehabilitative human care. The identification of possible safety issues in performance and environmental situations, and implications for care are critical to ensure safe and valuable rehabilitative health care practices for the elderly population.展开更多
Objective To explore the effects of exposure to aluminum (AI) on long-term potentiation (LTP) and AMPA receptor subunits in rats in vivo. Methods Different dosages of aluminum-maltolate complex [Al(mal)3] were g...Objective To explore the effects of exposure to aluminum (AI) on long-term potentiation (LTP) and AMPA receptor subunits in rats in vivo. Methods Different dosages of aluminum-maltolate complex [Al(mal)3] were given to rats via acute intracerebroventricular (i.c.v.) injection and subchronic intraperitoneal (i.p.) injection. Following AI exposure, the hippocampal LTP were recorded by field potentiation technique in vivo and the expression of AMPAR subunit proteins (GluR1 and GluR2) in both total and membrane-enriched extracts from the CA1 area of rat hippocampus were detected by Western blot assay. Results Acute AI treatment produced dose-dependent suppression of LTP in the rat hippocampus and dose-dependent decreases of GluRz and GluR2 in membrane extracts; however, no similar changes were found in the total cell extracts, which suggests decreased trafficking of AMPA receptor subunits from intracellular pools to synaptic sites in the hippocampus. The dose-dependent suppressive effects on LTP and the expression of AMPA receptor subunits both in the membrane and in total extracts were found after subchronic AI treatment, indicating a decrease in AMPA receptor subunit trafficking from intracellular pools to synaptic sites and an additional reduction in the expression of the subunits. Conclusion Al(mal)3 obviously and dose-dependently suppressed LTP in the rat hippocampal CA1 region in vivo, and this suppression may be related to both trafficking and decreases in the expression of AMPA receptor subunit proteins. However, the mechanisms underlying these observations need further investigation.展开更多
Objective To explore the role of RAS/PI3K pathway in the impairment of long-term potentiation (LTP) induced by acute aluminum (AI) treatment in rats in vivo. Methods First, different dosages of aluminum-maltolate ...Objective To explore the role of RAS/PI3K pathway in the impairment of long-term potentiation (LTP) induced by acute aluminum (AI) treatment in rats in vivo. Methods First, different dosages of aluminum-maltolate complex [Al(mal)3] were given to rats via acute intracerebroventricular (i.c.v.) injection. Following AI exposure, the RAS activity of rat hippocampus were detected by ELISA assay after the hippocampal LTP recording by field potentiation technique in vivo. Second, the antagonism on the aluminum-induced suppression of hippocampal LTP was observed after the treatment of the RAS activator epidermal growth factor (EGF). Finally, the antagonism on the downstream molecules (PKB activity and the phosphorylation of GluR1 $831 and $845) were tested by ELISA and West-blot assays at the same time. Results With the increasing aluminum dosage, a gradually decreasing in RAS activity of the rat hippocampus was produced after a gradually suppressing on LTP. The aluminum-induced early suppression of hippocampal LTP was antagonized by the RAS activator epidermal growth factor (EGF). And the EGF treatment produced changes similar to those observed for LTP between the groups on PKB activity as well as the phosphorylation of GluR1 S831 and s845. Conclusion The RAS-PI3K/PKB-GluR1 S831 and S845 signal transduction pathway may be involved in the inhibition of hippocampal LTP by aluminum exposure in rats. However, the mechanisms underlying this observation need further investigation.展开更多
Objective To explore the changes in spatial learning performance and long-term potentiation (LTP) which is recognized as a component of the cellular basis of learning and memory in normal and lead-exposed rats after...Objective To explore the changes in spatial learning performance and long-term potentiation (LTP) which is recognized as a component of the cellular basis of learning and memory in normal and lead-exposed rats after administration of melatonin (MT) for two months. Methods Experiment was performed in adult male Wistar rats (12 controls, 12 exposed to melatonin treatment, 10 exposed to lead and 10 exposed to lead and melatonin treatment). The lead-exposed rats received 0.2% lead acetate solution from their birth day while the control rats drank tap water. Melatonin (3 mg/kg) or vehicle was administered to the control and lead-exposed rats from the time of their weaning by gastric gavage each day for 60 days, depending on their groups. At the age of 81-90 days, all the animals were subjected to Morris water maze test and then used for extracellular recording of LTP in the dentate gyrus (DG) area of the hippocampus in vivo. Results Low dose of melatonin given from weaning for two months impaired LTP in the DG area of hippocampus and induced learning and memory deficit in the control rats. When melatonin was administered over a prolonged period to the lead-exposed rats, it exacerbated LTP impairment, learning and memory deficit induced by lead. Conclusion Melatonin is not suitable for normal and lead-exposed children.展开更多
Liuwei Dihuang decoction(LW), a classic formula in traditional Chinese medicine(TCM), has been used for nearly one thousand years for various diseases with characteristic features of kidney yin deficiency. LW consists...Liuwei Dihuang decoction(LW), a classic formula in traditional Chinese medicine(TCM), has been used for nearly one thousand years for various diseases with characteristic features of kidney yin deficiency. LW consists of 6herbs including Dihuang[prepared root of Rehmannia glutinosa(Gaertn) DC], Shanyao(rhizome of Dioscorea polystachya Turcz), Shanzhuyu(fruit of Cornus officinalis Siebold Zucc), Mudanpi(root bark of Paeonia × suffruticosa Andrews),Zexie(rhizome of Alisma plantago-aquatica L) and Fuling(scleorotia of Wolfiporia extensa(Peck) Ginns)LW-active fraction combination(LW-AFC) is extracted from LW, it is effective for the treatment of kidney yin deficiency in many animal models. There are 3 fractions in LW-AFC, a polysaccharide fraction(LWB-B), a glycoside fraction(LWD-b) and an oligosaccharide fraction(CA-30). Our previous results indicate that LW-AFC has similar pharmacological effects to LW, modulating the balance of the NIM network. LW-AFC has positive effects in many animal models of kidney deficiency or disturbance of the NIM network. LW-AFC could improve the cognitive ability in Alzheimer′s disease(AD) animal models(APP/PS1, SAMP8), where modulating immune function and balancing the NIM network may play an important role in its cognition improving effects. Our study also showed that LW-AFC had protective effects on stress-induced disturbances of the NIM network. However, the underlying mechanisms remain elusive and need further investigation. OBJECTIVE This study evaluated the effects of LW-AFC and the active fractions(polysaccharide, LWB-B;glycoside, LWD-b;oligosaccharide,CA-30) on corticosterone(Cort)-induced long-term potentiation(LTP) impairment in vivo. METHODS LTP was used to evaluate the synaptic plasticity. LW-AFC was orally administered for seven days. The active fractions were given by either chronic administration(ig, ip, 7 d) or single administration(icv, ig, ip). Cort was injected subcutaneously 1 h before the high-frequency stimulation(HFS) to induce LTP impairment. Moreover, in order to research on the possible effective pathways, an antibiotic cocktail and an immunosuppressant were also used. RESULTS Chronic administration(ig) of LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment. Single administration(icv, ig, ip) of any of the active fractions had no effect on Cort-induced LTP impairment, while chronic administration(ig, ip) of LWB-B or LWD-b showed positive effects against Cort. Interestingly, CA-30 only showed protective effects via ig administration,and there was little effect when CA-30 was administered ip In addition, when the intestinal microbiota was disrupted by application of the antibiotic cocktail, CA-30 showed little protective effects against Cort. The effects of LW-AFC were also abolished when the immune function was inhibited. In the hippocampal tissue, Cort treatment increased corticosterone and glutamate, and LW-AFC could inhibit the Cort-induced elevation of corticosterone and glutamate;there was little change in D-serine in Cort-treated animals, but LW-AFC could increase the D-serine levels. CONCLUSION LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment. Their protective effects are unlikely by a direct way, and immune modulation might be the common pathway. CA-30 could protect LTP from impairment via modulating the intestinal microbiota. Decreasing corticosterone and glutamate and increasing D-serine in the Cort-treated animals’ hippocampal tissue might be one of the mechanisms for the neural protective effects of LW-AFC. Further study is needed to understand the underlying mechanisms.展开更多
Purpose: To study the property of LTP in layers Ⅱ~Ⅳof the rats visual cortex at different postnatal days induced by pairing low-frequency stimulation at layer Ⅳ with post synaptic depolarization in order to explor...Purpose: To study the property of LTP in layers Ⅱ~Ⅳof the rats visual cortex at different postnatal days induced by pairing low-frequency stimulation at layer Ⅳ with post synaptic depolarization in order to explore the synaptic and cellular mechanism of experience-dependent plasticity in the visual cortex.Methods: Postsynaptic currents (PSCs) of layers Ⅱ~Ⅳ in visual cortex slices of Wistar rats aged P0-29 d were recorded by patch-clamp whole cell recording method. Long-term potentiation (LTP) was induced by low-frequency stimulation (LFS) at 1Hz for 60~90 s.Each pulse of the LFS paired with depolarization of post-synaptic neurons to -20 mV.100μM APV, a kind of competitive N-methyl-d-aspartate (NMDA) receptor antagonist, was both applied to some slices to test the property of LTP.Results: 1. The LTP incidence was very low before P10d (5/34), and increased rapidly to the top at P15-24 d (17/28), then decreased sharply to 1/5 at P25-29 d, coinciding well with the critical period of plasticity of rat visual cortex. The LTP incidence of P15-29d (after eye opening, 18/33) was significantly higher than that of P0-14 d (before eye opening, 12/43, P < 0.05). 2. Compared with non-APV applied group (30/76), LTP incidence of APV applied group (4/33) was significantly decreased (P < 0.01 ). There were 4 Ⅳ-Ⅳ horizontal synapses. APV application could not block the LTP induction.Conclusions: 1. LTP was a reflection of naturally occurring, experience-dependent plasticity in rat visual cortex. The patterned visual stimuli received after eye opening might be an activation factor of the synaptic plasticity. 2. LTP of visual cortex induced by LFS in layer Ⅳ paired with postsynaptic depolarization was NMDA receptor dependent during the critical period of visual plasticity. However, there were LTP existed in Ⅳ-Ⅳ horizontal synapses which could not be blocked by 100μM APV.展开更多
Experiments were performed on 64 Sprague-Dawley rats under ure-thane anesthesia. Extracellular recording method was used to investigate the effect of aluminum (Al)microinjected into CA3 on long-term potentiation (LTP)...Experiments were performed on 64 Sprague-Dawley rats under ure-thane anesthesia. Extracellular recording method was used to investigate the effect of aluminum (Al)microinjected into CA3 on long-term potentiation (LTP) in this area. The relationship between the inhibitory effect of Al and L-arginine-NO pathway was also studied. Microinjection of Al (0. 5 mol/L, 1 μl ) into CA3 could block the induction of LTP in CA3. Microinjection of Al (0. 5 mol/L, 1 μl) into CA3 after LTP was induced could also decrease the amplitude of population spike (PS). The inhibitory effect of Al on LTP in CA3 could be enhanced by preinjection of NG-nitro-L-arginine (0. 3 mol/L, 1 μl). Preinjection of L-arginine (0. 3 mol/L, 1 μl) into CA3 could antagonize the inhibitory effect of Al on LTP. These results suggest that Al could block the induction of LTP and decrease the amplitude of PS potentiated in CA3. The effect of Al might be antagonized by L-arginine-NO pathway.展开更多
BACKGROUND: Brain injury patients often exhibit learning and memory functional deficits. Long-term potentiation (LTP) is a representative index for studying learning and memory cellular models; the LTP index correl...BACKGROUND: Brain injury patients often exhibit learning and memory functional deficits. Long-term potentiation (LTP) is a representative index for studying learning and memory cellular models; the LTP index correlates to neural plasticity. OBJECTIVE: This study was designed to investigate correlations of learning and memory functions to LTP in brain injury patients, and to summarize the research advancements in mechanisms underlying brain functional improvements after rehabilitation intervention. RETRIEVAL STRATEGY: Using the terms "brain injuries, rehabilitation, learning and memory, long-term potentiation", manuscripts that were published from 2000-2007 were retrieved from the PubMed database. At the same time, manuscripts published from 2000-2007 were also retrieved from the Database of Chinese Scientific and Technical Periodicals with the same terms in the Chinese language. A total of 64 manuscripts were obtained and primarily screened. Inclusion criteria: studies on learning and memory, as well as LTP in brain injury patients, and studies focused on the effects of rehabilitation intervention on the two indices; studies that were recently published or in high-impact journals. Exclusion criteria: repetitive studies. LITERATURE EVALUATION: The included manuscripts primarily focused on correlations between learning and memory and LTP, the effects of brain injury on learning and memory, as well as LTP, and the effects of rehabilitation intervention on learning and memory after brain injury. The included 39 manuscripts were clinical, basic experimental, or review studies. DATA SYNTHESIS: Learning and memory closely correlates to LTP. The neurobiological basis of learning and memory is central nervous system plasticity, which involves neural networks, neural circuits, and synaptic connections, in particular, synaptic plasticity. LTP is considered to be an ideal model for studying synaptic plasticity, and it is also a classic model for studying neural plasticity of learning and memory. Brain injury patients clinically present with various manifestations, such as paralysis and sensory disability, which closely correlate to injured regions. In addition, learning and memory abilities decrease in brain injury patients and LTP decreases following brain injury. Brain tissue injury will lead to brain functional deficits. Hippocampal LTP is very sensitive. Difficulties in LTP induction are apparent even prior to morphological changes in brain tissue. There are no specific treatments for learning and memory functional deficits following brain injury. At present, behavioral and compensative therapies are the typical forms of rehabilitation. These results indicate that rehabilitation promotes learning and memory functional recovery in brain injury patients by speeding up LTP formation in the hippocampal CA3 region. CONCLUSION: Rehabilitation intervention increases LTP formation in the hippocampal CA3 region and recovers learning and memory functions in brain injury patients.展开更多
The present study stimulated Baihui (DU 20) and Dazhui (DU 14) acupoints in a rat model of vascular dementia with electroacupuncture to investigate changes in long-term potentiation and synaptophysin expression in...The present study stimulated Baihui (DU 20) and Dazhui (DU 14) acupoints in a rat model of vascular dementia with electroacupuncture to investigate changes in long-term potentiation and synaptophysin expression in the hippocampus. The results revealed that synaptophysin expression in brain tissues was increased after electroacupuncture. After high4requency stimulation, the population spike latency was shortened and the excitatory postsynaptic potential slope and population spike amplitude were increased. In addition, cognitive function was enhanced, similar to the effects of intragastric perfusion of nimodipine. The results indicated that electroacupuncture at Baihui and Dazhui acupoints can improve learning and memory functions of a rat model of vascular dementia by promoting synaptophysin expression, enhancing hippocampal synaptic plasticity and accelerating synaptic transmission.展开更多
OBJECTIVE LW-AFC is extracted from the classical traditional Chinese medicinal prescription-Liuwei Dihuang Decoction.Previous studies have showed that LW-AFC could improve learning&memory ability in amny animal mo...OBJECTIVE LW-AFC is extracted from the classical traditional Chinese medicinal prescription-Liuwei Dihuang Decoction.Previous studies have showed that LW-AFC could improve learning&memory ability in amny animal models.In this study,we focused on evaluating the effect of several main active components fromLW-AFC(B-B;loganin,LOG;morroniside,MOR;paeoniflorin,PF and stachyose,STA)on LTP.METHODS In vivo recording of LTP was used in this study to evaluate the effects of LW-AFC and it′s active components on coticorsterone(Cort)induced LTP impairment.RESULTS The results showed that LW-AFC could ameliorate Cort-induced LTP impairment.The effect of LW-AFC was abolished when the immune function was inhibited.Single administration(ig,ip,icv)of any of the components had no effect on Cort-induced LTP impairment.Consecutively intragastric administration or intraperitoneal injections(chronic administration)of B-B,LOG,MOR or PF for 7 d showed protective effect on Cort-induced LTP impairment.Intragastric administration of STA for 7 d protected LTP from impairment induced by Cort,while there was little improving effect when STA was administrated via intraperitoneal injection.In addition,when the intestinal microbiota was disrupted by applying the antibiotic cocktail,STA showed little protective effect against Cort.CONCLUSION In conclusion,LW-AFC and it′s components showed positive effects against cort induced LTP impairment,it seems that all displayed protective effects via indirectly,immune modulation might be the common pathway for all components;the exact pathways are different in each component,B-B,LOG,MOR and PF could be absorbed into the bloods tream and then modulate the peripheral immune function,while STA could not be absorbed and modulates the immune function via modulating intestinal microbiota.Further studies are needed to invesgate the underlying mechanisms and the synergetic effects of all components.展开更多
OBJECTIVE Liuwei Dihuang Decoction(LW)-active fraction combination(LW-AFC,consist of 3 fractions polysaccharide,LWB-B;glycoside,LWD-b;oligosaccharide,CA-30)is extracted from LW,it is effective for the treatment of kid...OBJECTIVE Liuwei Dihuang Decoction(LW)-active fraction combination(LW-AFC,consist of 3 fractions polysaccharide,LWB-B;glycoside,LWD-b;oligosaccharide,CA-30)is extracted from LW,it is effective for the treatment of kidney yin deficiency in many animal models.This study evaluated the effects and mechanisms of LW-AFC and the active fractions on corticosterone(Cort)-induced long-term potentiation(LTP)impairment in vivo.METHODS LTP was used to evaluate the synaptic plasticity.LW-AFC was orally administered for seven days.The active fractions were given by either chronic administration(ig,ip,7 d)or single administration(icv,ig,ip).Cort was injected subcutaneously 1h before the high-frequency stimulation(HFS)to induce LTP impairment.Moreover,in order to research on the possible effective pathways,an antibiotic cocktail and an immunosuppressant were also used.RESULTS Chronic administration(ig)of LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment.Single administration(icv,ig,ip)of any of the active fractions had no effect on Cort-induced LTP impairment,while chronic administration(ig,ip)of LWB-B or LWD-b showed positive effects against Cort.Interestingly,CA-30 only showed protective effects via ig administration,and there was little effect when CA-30 was administered ip In addition,when the intestinal microbiota was disrupted by application of the antibiotic cocktail,CA-30 showed little protective effects against Cort.The effects of LW-AFC were also abolished when the immune function was inhibited.In the hippocampal tissue,Cort treatment increased Cort and glutamate,and LW-AFC could inhibit the Cort-induced elevation of Cort and glutamate;there was little change in D-serine in Cort-treated animals,but LW-AFC could increase the D-serine levels.CONCLUSION LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment.Their protective effects are unlikely by a direct way,and immune modulation might be the common pathway.CA-30 could protect LTP from impairment via modulating the intestinal microbiota.Decreasing Cort and glutamate and increasing D-serine in the Cort-treated animals'hippocampal tissue might be one of the mechanisms for the neural protective effects of LW-AFC.Further study is needed to understand the underlying mechanisms.展开更多
Very little is known about visual functional recovery following long-term naltrexone administration in opioid-dependent patients. In the present study, a portable event-related potential (ERP) working system was uti...Very little is known about visual functional recovery following long-term naltrexone administration in opioid-dependent patients. In the present study, a portable event-related potential (ERP) working system was utilized to collect and record ERP in opioid-dependent patients and normal controls in visual half-field testing. In addition, the influence of long-term sustained naltrexone release on the visual nervous system was observed in opioid-dependent patients. Results revealed a significant main group effect in reaction time to visual signal stimulations. The reaction time of normal controls was shortest, but longest in opioid-dependent patients. The reaction time of long-term sustained naltrexone release group and compulsory detoxification group was similar to normal controls. A significant main group effect was also observed in P100 latency, and P100 latency in normal controls and the compulsory detoxification group was significantly decreased compared with the opioid-dependent patients. P100 amplitude at the Oz-electrode resulted in a significant main group effect. In particular, normal controls exhibited significant differences compared with long-term sustained release naltrexone and compulsory detoxification groups. These findings demonstrated that long-term sustained naltrexone release effectively ameliorated optic center function and improved visual sensitivity and reactions in opioid-dependent patients.展开更多
The long-term enhancement in glutamate receptor mediated excitatory responses has been observed in stroke model. This pathological form of plasticity, termed post-ischemic long-term potentiation (i-LTP), points to f...The long-term enhancement in glutamate receptor mediated excitatory responses has been observed in stroke model. This pathological form of plasticity, termed post-ischemic long-term potentiation (i-LTP), points to functional reorganization after stroke. Little is known, however, about whether and how this i-LTP would affect subsequent induction of synaptic plasticity. Here, we first directly confirmed that i-LTP was induced in the endothelin-l-induced ischemia model as in other in vitro models. We also demonstrated increased expression of NR2B, CaMKII and p-CaMKII, which are reminiscent of i-LTP. We further induced LTP of field excitatory post- synaptic potentials (fEPSPs) on CA1 hippocampal neurons in peri-infarct regions of the endothelin-l-induced mini-stroke model. We found that LTP of fEPSPs, induced by high-frequency stimulation, displayed a progressive impairment at 12 and 24 hours after ischemia. Moreover, using in vivo multi-channel recording, we found that the local field potential, which represents electrical property of cell ensembles in more restricted regions, was also dam- pened at these two time points. These results suggest that i-LTP elevates the induction threshold of subsequent synap- tic plasticity. Our data helps to deepen the knowledge of meta-synaptic regulation of plasticity after focal ischemia.展开更多
基金the National Natural Science Foundation of China(No.30200076,30370474,30570599)Department of Science and Technology of Guangdong Province,China(No.2005A30801002)
文摘Long-term potentiation(LTP) of C-fiber evoked field potentials in spinal dorsal horn is first reported in 1995.Since then,the mechanisms underlying the long-lasting enhancement in synaptic transmission between primary afferent C-fibers and neurons in spinal dorsal horn have been investigated by different laboratories.In this article,the related data were summarized and discussed.
文摘BACKGROUND: Long-term potentiation of cornu dorsale medullae spinalis field potential in adult rats has already been reported; however, there is lack of correlated researches on naenonate, infant and adult rats which have different responses to pain conduction information.OBJECTIVE: To observe the various effects of electric stimulation at sciatic nerve on long-term potentiation of evoked field potential at superficial layer of cornu dorsale medullae spinalis of rats at various developmental phases and analyze manifestations of pain conduction information at superficial layers ( Ⅰ - Ⅱ)of cornu dorsale medullae spinalis in immature rats.DESIGN: Grouping controlled study.SETTING: Department of Physiology, Medical College of Wuhan University.MATERIALS: The experiment was carried out in the Laboratory of Physiology (provincial laboratory),Medical College of Wuhan University from March 2006 to May 2007. A total of 27 healthy male Sprague-Dawley (SD) rats, 17- 90 days old, SPF grade, weighing 41 -200 g, were provided by Experimental Animal Center, Medical College of Wuhan University.METHODS: Based on their birthdays, rats were divided into naenonate group (17 - 20 days old, weighing 41-52 g, n =10), infant group (35 - 50 days old, weighing 87 - 125 g, n =10) and adult group (60 - 90 days old, weighing 180 -200 g, n =7). Left sciatic nerve was separated and stimulated with single square wave (15 V, 0.5 ms). Meanwhile, evoked field potential was recorded at superficial layers of lateral T13 - L1 cornu dorsale medullae spinalis and then stimulated with high-frequent and high-intensive tetanizing current (30 -40 V, 0.5 ms, 100 Hz, 1s per bundle, 10s in bundle interval) four times. After the operation, onset of long-term potentiation was observed; meanwhile, amplitude changes and latency of field potential were analyzed.MAIN OUTCOME MEASURES: Amplitude and latency changes of field potential at superficial layers of cornu dorsale medullae spinalis of rats in the three groups.RESULTS: A total of 27 accepted rats were involved in the final analysis. ① Amplitude changes: Electric stimulation at sciatic nerve with high-frequent and high-intensive tetanizing current could induce evoked field potential at superficial layers (Ⅰ-Ⅱ ) of cornu dorsale medullae spinalis in the three groups.Long-term potentiation in the naenonate group manifested that amplitude of A-kind never fiber was raised and there was significant difference (P〈0.05). In addition, average amplitude was increased and there was obviously significant difference (P〈0.01). Long-term potentiation in the infant group manifested that amplitude of C-kind never fiber was raised and there was significant difference (P〈0.01); while, long-term potentiation in the adult group manifested that amplitude of C-kind never fiber was raised and there was significant difference (P〈0.01). Otherwise, latencies in the three groups were all shortened. ② Latency changes: Average latency of A-kind nerve fiber in the naenonate group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of C-kind nerve fiber was low and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation (P〉0.05). Average latency of C-kind nerve fiber in the infant group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of A-kind nerve fiber was stable and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation (P〉0.05). Average latency of C-kind nerve fiber in the adult group was shortened and there was significant difference (P〈0.01); in addition, evoked potential of A-kind nerve fiber was stable and latency was immovable. There was no significant difference before and after high-frequent and high-intensive electric stimulation.CONCLUSION: Evoked field potential at superficial layer of comu dorsale medullae spinalis can be recorded through electric stimulation at sciatic nerve. Single stimulation and tetanizing electric stimulation can cause different characteristics of evoked field potential in rats at various developmental phases.Superficial layer of cornu dorsale medullae spinalis of naenonate rats is mainly caused by A-kind nerve fiber which participants in pain conduction and formation of pain sensitivity; however, that of infant and adult rats mainly depends on C-kind nerve fiber.
文摘In Japan, the shortage of personnel is a problem in long-term care nursing and rehabilitative care prevention. Nevertheless, Japan has taken measures to compensate for these shortages by promoting medical and nursing care activities using robotic technologies, and employing human resources from overseas. The purpose of this study was to determine potential legal issues and subsequent implications for care during prevention gymnastic exercises for the elderly using Pepper in long-term health facilities. The application program of Care-Prevention Gymnastics Exercises for Pepper (Pepper with CPGE) was made by the Xing Company Japan. Currently, care workers become intermediaries for the safe use of Pepper with CPGE. However, it was realized that some legal issues may arise if Pepper with CPGE alone will carry out these preventive care programs for the elderly without the presence of care workers as intermediaries. In this situation, using Pepper with CPGE alone to conduct care prevention gymnastics will require safety measures to prevent these possible practice issues and anticipate implications for care. In this regard, determining detailed target levels of rehabilitation exercise demands and environmental setting safety become essential factors. The use of humanoid robots in healthcare is expected to influence more practice protocols in contemporary and futurist rehabilitative human care. The identification of possible safety issues in performance and environmental situations, and implications for care are critical to ensure safe and valuable rehabilitative health care practices for the elderly population.
基金supported by the Natural Science Foundation of China(NSFC,30972512 and 81202182)the Research Foundation for the Doctoral Program of Higher Education(20121417110002)
文摘Objective To explore the effects of exposure to aluminum (AI) on long-term potentiation (LTP) and AMPA receptor subunits in rats in vivo. Methods Different dosages of aluminum-maltolate complex [Al(mal)3] were given to rats via acute intracerebroventricular (i.c.v.) injection and subchronic intraperitoneal (i.p.) injection. Following AI exposure, the hippocampal LTP were recorded by field potentiation technique in vivo and the expression of AMPAR subunit proteins (GluR1 and GluR2) in both total and membrane-enriched extracts from the CA1 area of rat hippocampus were detected by Western blot assay. Results Acute AI treatment produced dose-dependent suppression of LTP in the rat hippocampus and dose-dependent decreases of GluRz and GluR2 in membrane extracts; however, no similar changes were found in the total cell extracts, which suggests decreased trafficking of AMPA receptor subunits from intracellular pools to synaptic sites in the hippocampus. The dose-dependent suppressive effects on LTP and the expression of AMPA receptor subunits both in the membrane and in total extracts were found after subchronic AI treatment, indicating a decrease in AMPA receptor subunit trafficking from intracellular pools to synaptic sites and an additional reduction in the expression of the subunits. Conclusion Al(mal)3 obviously and dose-dependently suppressed LTP in the rat hippocampal CA1 region in vivo, and this suppression may be related to both trafficking and decreases in the expression of AMPA receptor subunit proteins. However, the mechanisms underlying these observations need further investigation.
基金supported by the Natural Science Foundation of China(NSFC,81202182)the Doctoral startup Foundation of Shanxi Medical University(03201413)
文摘Objective To explore the role of RAS/PI3K pathway in the impairment of long-term potentiation (LTP) induced by acute aluminum (AI) treatment in rats in vivo. Methods First, different dosages of aluminum-maltolate complex [Al(mal)3] were given to rats via acute intracerebroventricular (i.c.v.) injection. Following AI exposure, the RAS activity of rat hippocampus were detected by ELISA assay after the hippocampal LTP recording by field potentiation technique in vivo. Second, the antagonism on the aluminum-induced suppression of hippocampal LTP was observed after the treatment of the RAS activator epidermal growth factor (EGF). Finally, the antagonism on the downstream molecules (PKB activity and the phosphorylation of GluR1 $831 and $845) were tested by ELISA and West-blot assays at the same time. Results With the increasing aluminum dosage, a gradually decreasing in RAS activity of the rat hippocampus was produced after a gradually suppressing on LTP. The aluminum-induced early suppression of hippocampal LTP was antagonized by the RAS activator epidermal growth factor (EGF). And the EGF treatment produced changes similar to those observed for LTP between the groups on PKB activity as well as the phosphorylation of GluR1 S831 and s845. Conclusion The RAS-PI3K/PKB-GluR1 S831 and S845 signal transduction pathway may be involved in the inhibition of hippocampal LTP by aluminum exposure in rats. However, the mechanisms underlying this observation need further investigation.
基金supported by the National Basic Research Program of China(No.2002CB512907)the National Natural Science Foundation of China(No.30630057).
文摘Objective To explore the changes in spatial learning performance and long-term potentiation (LTP) which is recognized as a component of the cellular basis of learning and memory in normal and lead-exposed rats after administration of melatonin (MT) for two months. Methods Experiment was performed in adult male Wistar rats (12 controls, 12 exposed to melatonin treatment, 10 exposed to lead and 10 exposed to lead and melatonin treatment). The lead-exposed rats received 0.2% lead acetate solution from their birth day while the control rats drank tap water. Melatonin (3 mg/kg) or vehicle was administered to the control and lead-exposed rats from the time of their weaning by gastric gavage each day for 60 days, depending on their groups. At the age of 81-90 days, all the animals were subjected to Morris water maze test and then used for extracellular recording of LTP in the dentate gyrus (DG) area of the hippocampus in vivo. Results Low dose of melatonin given from weaning for two months impaired LTP in the DG area of hippocampus and induced learning and memory deficit in the control rats. When melatonin was administered over a prolonged period to the lead-exposed rats, it exacerbated LTP impairment, learning and memory deficit induced by lead. Conclusion Melatonin is not suitable for normal and lead-exposed children.
文摘Liuwei Dihuang decoction(LW), a classic formula in traditional Chinese medicine(TCM), has been used for nearly one thousand years for various diseases with characteristic features of kidney yin deficiency. LW consists of 6herbs including Dihuang[prepared root of Rehmannia glutinosa(Gaertn) DC], Shanyao(rhizome of Dioscorea polystachya Turcz), Shanzhuyu(fruit of Cornus officinalis Siebold Zucc), Mudanpi(root bark of Paeonia × suffruticosa Andrews),Zexie(rhizome of Alisma plantago-aquatica L) and Fuling(scleorotia of Wolfiporia extensa(Peck) Ginns)LW-active fraction combination(LW-AFC) is extracted from LW, it is effective for the treatment of kidney yin deficiency in many animal models. There are 3 fractions in LW-AFC, a polysaccharide fraction(LWB-B), a glycoside fraction(LWD-b) and an oligosaccharide fraction(CA-30). Our previous results indicate that LW-AFC has similar pharmacological effects to LW, modulating the balance of the NIM network. LW-AFC has positive effects in many animal models of kidney deficiency or disturbance of the NIM network. LW-AFC could improve the cognitive ability in Alzheimer′s disease(AD) animal models(APP/PS1, SAMP8), where modulating immune function and balancing the NIM network may play an important role in its cognition improving effects. Our study also showed that LW-AFC had protective effects on stress-induced disturbances of the NIM network. However, the underlying mechanisms remain elusive and need further investigation. OBJECTIVE This study evaluated the effects of LW-AFC and the active fractions(polysaccharide, LWB-B;glycoside, LWD-b;oligosaccharide,CA-30) on corticosterone(Cort)-induced long-term potentiation(LTP) impairment in vivo. METHODS LTP was used to evaluate the synaptic plasticity. LW-AFC was orally administered for seven days. The active fractions were given by either chronic administration(ig, ip, 7 d) or single administration(icv, ig, ip). Cort was injected subcutaneously 1 h before the high-frequency stimulation(HFS) to induce LTP impairment. Moreover, in order to research on the possible effective pathways, an antibiotic cocktail and an immunosuppressant were also used. RESULTS Chronic administration(ig) of LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment. Single administration(icv, ig, ip) of any of the active fractions had no effect on Cort-induced LTP impairment, while chronic administration(ig, ip) of LWB-B or LWD-b showed positive effects against Cort. Interestingly, CA-30 only showed protective effects via ig administration,and there was little effect when CA-30 was administered ip In addition, when the intestinal microbiota was disrupted by application of the antibiotic cocktail, CA-30 showed little protective effects against Cort. The effects of LW-AFC were also abolished when the immune function was inhibited. In the hippocampal tissue, Cort treatment increased corticosterone and glutamate, and LW-AFC could inhibit the Cort-induced elevation of corticosterone and glutamate;there was little change in D-serine in Cort-treated animals, but LW-AFC could increase the D-serine levels. CONCLUSION LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment. Their protective effects are unlikely by a direct way, and immune modulation might be the common pathway. CA-30 could protect LTP from impairment via modulating the intestinal microbiota. Decreasing corticosterone and glutamate and increasing D-serine in the Cort-treated animals’ hippocampal tissue might be one of the mechanisms for the neural protective effects of LW-AFC. Further study is needed to understand the underlying mechanisms.
基金Supported by Chinese National Natural Science Found (grants Nos,39970252, 39770258, 30070254).
文摘Purpose: To study the property of LTP in layers Ⅱ~Ⅳof the rats visual cortex at different postnatal days induced by pairing low-frequency stimulation at layer Ⅳ with post synaptic depolarization in order to explore the synaptic and cellular mechanism of experience-dependent plasticity in the visual cortex.Methods: Postsynaptic currents (PSCs) of layers Ⅱ~Ⅳ in visual cortex slices of Wistar rats aged P0-29 d were recorded by patch-clamp whole cell recording method. Long-term potentiation (LTP) was induced by low-frequency stimulation (LFS) at 1Hz for 60~90 s.Each pulse of the LFS paired with depolarization of post-synaptic neurons to -20 mV.100μM APV, a kind of competitive N-methyl-d-aspartate (NMDA) receptor antagonist, was both applied to some slices to test the property of LTP.Results: 1. The LTP incidence was very low before P10d (5/34), and increased rapidly to the top at P15-24 d (17/28), then decreased sharply to 1/5 at P25-29 d, coinciding well with the critical period of plasticity of rat visual cortex. The LTP incidence of P15-29d (after eye opening, 18/33) was significantly higher than that of P0-14 d (before eye opening, 12/43, P < 0.05). 2. Compared with non-APV applied group (30/76), LTP incidence of APV applied group (4/33) was significantly decreased (P < 0.01 ). There were 4 Ⅳ-Ⅳ horizontal synapses. APV application could not block the LTP induction.Conclusions: 1. LTP was a reflection of naturally occurring, experience-dependent plasticity in rat visual cortex. The patterned visual stimuli received after eye opening might be an activation factor of the synaptic plasticity. 2. LTP of visual cortex induced by LFS in layer Ⅳ paired with postsynaptic depolarization was NMDA receptor dependent during the critical period of visual plasticity. However, there were LTP existed in Ⅳ-Ⅳ horizontal synapses which could not be blocked by 100μM APV.
基金This project was supported by grant from the National Nature Science Foundation of China (No.39270591)
文摘Experiments were performed on 64 Sprague-Dawley rats under ure-thane anesthesia. Extracellular recording method was used to investigate the effect of aluminum (Al)microinjected into CA3 on long-term potentiation (LTP) in this area. The relationship between the inhibitory effect of Al and L-arginine-NO pathway was also studied. Microinjection of Al (0. 5 mol/L, 1 μl ) into CA3 could block the induction of LTP in CA3. Microinjection of Al (0. 5 mol/L, 1 μl) into CA3 after LTP was induced could also decrease the amplitude of population spike (PS). The inhibitory effect of Al on LTP in CA3 could be enhanced by preinjection of NG-nitro-L-arginine (0. 3 mol/L, 1 μl). Preinjection of L-arginine (0. 3 mol/L, 1 μl) into CA3 could antagonize the inhibitory effect of Al on LTP. These results suggest that Al could block the induction of LTP and decrease the amplitude of PS potentiated in CA3. The effect of Al might be antagonized by L-arginine-NO pathway.
基金the Grant from Science and Technology Foundation of Sichuan Province, No. 2002-20
文摘BACKGROUND: Brain injury patients often exhibit learning and memory functional deficits. Long-term potentiation (LTP) is a representative index for studying learning and memory cellular models; the LTP index correlates to neural plasticity. OBJECTIVE: This study was designed to investigate correlations of learning and memory functions to LTP in brain injury patients, and to summarize the research advancements in mechanisms underlying brain functional improvements after rehabilitation intervention. RETRIEVAL STRATEGY: Using the terms "brain injuries, rehabilitation, learning and memory, long-term potentiation", manuscripts that were published from 2000-2007 were retrieved from the PubMed database. At the same time, manuscripts published from 2000-2007 were also retrieved from the Database of Chinese Scientific and Technical Periodicals with the same terms in the Chinese language. A total of 64 manuscripts were obtained and primarily screened. Inclusion criteria: studies on learning and memory, as well as LTP in brain injury patients, and studies focused on the effects of rehabilitation intervention on the two indices; studies that were recently published or in high-impact journals. Exclusion criteria: repetitive studies. LITERATURE EVALUATION: The included manuscripts primarily focused on correlations between learning and memory and LTP, the effects of brain injury on learning and memory, as well as LTP, and the effects of rehabilitation intervention on learning and memory after brain injury. The included 39 manuscripts were clinical, basic experimental, or review studies. DATA SYNTHESIS: Learning and memory closely correlates to LTP. The neurobiological basis of learning and memory is central nervous system plasticity, which involves neural networks, neural circuits, and synaptic connections, in particular, synaptic plasticity. LTP is considered to be an ideal model for studying synaptic plasticity, and it is also a classic model for studying neural plasticity of learning and memory. Brain injury patients clinically present with various manifestations, such as paralysis and sensory disability, which closely correlate to injured regions. In addition, learning and memory abilities decrease in brain injury patients and LTP decreases following brain injury. Brain tissue injury will lead to brain functional deficits. Hippocampal LTP is very sensitive. Difficulties in LTP induction are apparent even prior to morphological changes in brain tissue. There are no specific treatments for learning and memory functional deficits following brain injury. At present, behavioral and compensative therapies are the typical forms of rehabilitation. These results indicate that rehabilitation promotes learning and memory functional recovery in brain injury patients by speeding up LTP formation in the hippocampal CA3 region. CONCLUSION: Rehabilitation intervention increases LTP formation in the hippocampal CA3 region and recovers learning and memory functions in brain injury patients.
基金the Natural Science Foundation of Zhejiang Province, No. Y208445 the Natural Science Foundation of Ningbo Science and Technology Bureau, No. 2009A610161 K.C. Wong Magna Fund from Ningbo University
文摘The present study stimulated Baihui (DU 20) and Dazhui (DU 14) acupoints in a rat model of vascular dementia with electroacupuncture to investigate changes in long-term potentiation and synaptophysin expression in the hippocampus. The results revealed that synaptophysin expression in brain tissues was increased after electroacupuncture. After high4requency stimulation, the population spike latency was shortened and the excitatory postsynaptic potential slope and population spike amplitude were increased. In addition, cognitive function was enhanced, similar to the effects of intragastric perfusion of nimodipine. The results indicated that electroacupuncture at Baihui and Dazhui acupoints can improve learning and memory functions of a rat model of vascular dementia by promoting synaptophysin expression, enhancing hippocampal synaptic plasticity and accelerating synaptic transmission.
文摘OBJECTIVE LW-AFC is extracted from the classical traditional Chinese medicinal prescription-Liuwei Dihuang Decoction.Previous studies have showed that LW-AFC could improve learning&memory ability in amny animal models.In this study,we focused on evaluating the effect of several main active components fromLW-AFC(B-B;loganin,LOG;morroniside,MOR;paeoniflorin,PF and stachyose,STA)on LTP.METHODS In vivo recording of LTP was used in this study to evaluate the effects of LW-AFC and it′s active components on coticorsterone(Cort)induced LTP impairment.RESULTS The results showed that LW-AFC could ameliorate Cort-induced LTP impairment.The effect of LW-AFC was abolished when the immune function was inhibited.Single administration(ig,ip,icv)of any of the components had no effect on Cort-induced LTP impairment.Consecutively intragastric administration or intraperitoneal injections(chronic administration)of B-B,LOG,MOR or PF for 7 d showed protective effect on Cort-induced LTP impairment.Intragastric administration of STA for 7 d protected LTP from impairment induced by Cort,while there was little improving effect when STA was administrated via intraperitoneal injection.In addition,when the intestinal microbiota was disrupted by applying the antibiotic cocktail,STA showed little protective effect against Cort.CONCLUSION In conclusion,LW-AFC and it′s components showed positive effects against cort induced LTP impairment,it seems that all displayed protective effects via indirectly,immune modulation might be the common pathway for all components;the exact pathways are different in each component,B-B,LOG,MOR and PF could be absorbed into the bloods tream and then modulate the peripheral immune function,while STA could not be absorbed and modulates the immune function via modulating intestinal microbiota.Further studies are needed to invesgate the underlying mechanisms and the synergetic effects of all components.
文摘OBJECTIVE Liuwei Dihuang Decoction(LW)-active fraction combination(LW-AFC,consist of 3 fractions polysaccharide,LWB-B;glycoside,LWD-b;oligosaccharide,CA-30)is extracted from LW,it is effective for the treatment of kidney yin deficiency in many animal models.This study evaluated the effects and mechanisms of LW-AFC and the active fractions on corticosterone(Cort)-induced long-term potentiation(LTP)impairment in vivo.METHODS LTP was used to evaluate the synaptic plasticity.LW-AFC was orally administered for seven days.The active fractions were given by either chronic administration(ig,ip,7 d)or single administration(icv,ig,ip).Cort was injected subcutaneously 1h before the high-frequency stimulation(HFS)to induce LTP impairment.Moreover,in order to research on the possible effective pathways,an antibiotic cocktail and an immunosuppressant were also used.RESULTS Chronic administration(ig)of LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment.Single administration(icv,ig,ip)of any of the active fractions had no effect on Cort-induced LTP impairment,while chronic administration(ig,ip)of LWB-B or LWD-b showed positive effects against Cort.Interestingly,CA-30 only showed protective effects via ig administration,and there was little effect when CA-30 was administered ip In addition,when the intestinal microbiota was disrupted by application of the antibiotic cocktail,CA-30 showed little protective effects against Cort.The effects of LW-AFC were also abolished when the immune function was inhibited.In the hippocampal tissue,Cort treatment increased Cort and glutamate,and LW-AFC could inhibit the Cort-induced elevation of Cort and glutamate;there was little change in D-serine in Cort-treated animals,but LW-AFC could increase the D-serine levels.CONCLUSION LW-AFC and its three active fractions could ameliorate Cort-induced LTP impairment.Their protective effects are unlikely by a direct way,and immune modulation might be the common pathway.CA-30 could protect LTP from impairment via modulating the intestinal microbiota.Decreasing Cort and glutamate and increasing D-serine in the Cort-treated animals'hippocampal tissue might be one of the mechanisms for the neural protective effects of LW-AFC.Further study is needed to understand the underlying mechanisms.
基金the Natural Science Foundation of Guangdong Province,No. 06027973the Science and Technology Development Program of Guangdong Province,No. 2004B3600105the Medical Science Foundation Program of Guangdong Province,No. A2007592
文摘Very little is known about visual functional recovery following long-term naltrexone administration in opioid-dependent patients. In the present study, a portable event-related potential (ERP) working system was utilized to collect and record ERP in opioid-dependent patients and normal controls in visual half-field testing. In addition, the influence of long-term sustained naltrexone release on the visual nervous system was observed in opioid-dependent patients. Results revealed a significant main group effect in reaction time to visual signal stimulations. The reaction time of normal controls was shortest, but longest in opioid-dependent patients. The reaction time of long-term sustained naltrexone release group and compulsory detoxification group was similar to normal controls. A significant main group effect was also observed in P100 latency, and P100 latency in normal controls and the compulsory detoxification group was significantly decreased compared with the opioid-dependent patients. P100 amplitude at the Oz-electrode resulted in a significant main group effect. In particular, normal controls exhibited significant differences compared with long-term sustained release naltrexone and compulsory detoxification groups. These findings demonstrated that long-term sustained naltrexone release effectively ameliorated optic center function and improved visual sensitivity and reactions in opioid-dependent patients.
基金supported by Major State Basic Research Program of China(Grant No.2013CB733801)
文摘The long-term enhancement in glutamate receptor mediated excitatory responses has been observed in stroke model. This pathological form of plasticity, termed post-ischemic long-term potentiation (i-LTP), points to functional reorganization after stroke. Little is known, however, about whether and how this i-LTP would affect subsequent induction of synaptic plasticity. Here, we first directly confirmed that i-LTP was induced in the endothelin-l-induced ischemia model as in other in vitro models. We also demonstrated increased expression of NR2B, CaMKII and p-CaMKII, which are reminiscent of i-LTP. We further induced LTP of field excitatory post- synaptic potentials (fEPSPs) on CA1 hippocampal neurons in peri-infarct regions of the endothelin-l-induced mini-stroke model. We found that LTP of fEPSPs, induced by high-frequency stimulation, displayed a progressive impairment at 12 and 24 hours after ischemia. Moreover, using in vivo multi-channel recording, we found that the local field potential, which represents electrical property of cell ensembles in more restricted regions, was also dam- pened at these two time points. These results suggest that i-LTP elevates the induction threshold of subsequent synap- tic plasticity. Our data helps to deepen the knowledge of meta-synaptic regulation of plasticity after focal ischemia.