Effect of tetramethylpyrazine on the spatial learning and memory function of rats after focal cerebral ischemia

BACKGROUND： Tetramethylpyrazine （TMP） presents the effect of anti-platelet aggregation, reduces arteria resistance, increases cerebral blood flow, and improves microcirculation. OBJECTIVE： To observe the effects of TMP on the learning and memory abilities and the number of neurons in cortex and hippocampus after focal cerebral ischemia in rats DESIGN： A randomized controlled tria SETTING： Department of Human Anatomy and Histological Embryology, School of Medicine, Xi＇an Jiaotong University. MATERIALS： Fifty adult male Sprague-Dawley rats, weighing 250-300 g were supplied by the Experimental Animal Center, School of Medicine, Xi＇an Jiaotong University. TMP was purchased from Wuxi Seventh Pharmaceutical Co.Ltd （Lot Number： 2004051106, Specification： 2 mL/piece）. METHODS ： The experiments were carried out in School of Medicine of Xi＇an Jiaotong University from June 2004 to May 2005. The 50 rats were randomly divided into five groups according to the random number table method： sham-operated group, cerebral ischemia control group, low-dose TMP group, middle-dose TMP group and high-dose TMP group, 10 rats in each group. Rats in the TMP groups were immediately treated with intraperitoneal injection of TMP of 40, 80 and 120 mg/kg respectively, and those in the sham-operated group and cerebral ischemia control group were injected intraperitoneally by isovolume saline, once a day for 14 days successively. On the 15^th day, the spatial learning and memory abilities of the rats were assessed with the Morris water maze test, and then the changes of neuron numbers in cortex and hippocampus were observed by Nissl staining of brain sections. MAIN OUTCOME MEASURES ： The results of Morris water maze test and the changes of neuron numbers in cortex and hippocampus by Nissl staining of brain sections were observed. RESULTS： Finally 39 rats were involved in the analysis of results, and the other 11 died of excessive anesthesia or failure in model establishment. ① The rats in the cerebral ischemia control group manifested obvious spatial cognitive deficits in the place navigation trial and spatial probe trial. The mean values of escape latency in the sham-operated group, low, middle and high-dose TMP groups were obviously shorter than that in the cerebral ischemia control group [（23.92±2.21）, （41.84±3.74）, （39.50 ±3.80）, （31.38_±3.72）, （61.60±3.61） s, P 〈 0.05-0.01]. In the spatial probe trial, significant differences in the percentage of time spending in the former platform quadrant and frequency of crossing the former platform site in the sham-operated group, lose, middle and high-dose TMP groups were obviously higher or more than those in the cerebral ischemia control group [（36.27±3.42） %, （35.84±2.54）%, （38.43±3.08）%, （36.51±1.96）%, （22.24±3.46）%; （11 ±1 ）, （10±1）, （8_±1）, （8±1）, （4±1） times, P 〈 0.01]. ② In the morphological observation, the numbers of neurons in ipsilateral （left） parietal cortex in the sham-operated group, low, middle and high-dose TMP groups were obviously more than that in the cerebral ischemia control group [（98±8）, （65±5）, （53±6）, （57±6）, （37±6）/0.625 mm^2, P 〈 0.01], but the number of neurons in left hippocampus had no obvious differences among the groups （P 〉 0.05）. CONCLUSION ： TMP can improve obviously the spatial learning and memory function after permanent focal cerebral ischemia in rats, and the neuroprotective role of the drug in cortex may be involved in its mechanism.

Improvement of learning and memory abilities and motor function in rats with cerebral infarction by intracerebral transplantation of neuron-like cells derived from bone marrow stromal cells

BACKGROUND： Transplantation of fetal cell suspension or blocks of fetal tissue can ameliorate the nerve function after the injury or disease in the central nervous system, and it has been used to treat neurodegenerative disorders induced by Parkinson disease. OBJECTIVE： To observe the effects of the transplantation of neuron-like cells derived from bone marrow stromal cells （rMSCs） into the brain in restoring the dysfunctions of muscle strength and balance as well as learning and memory in rat models of cerebral infarction. DESIGN ： A randomized controlled experiment.SETTING ： Department of Pathophysiology, Zhongshan Medical College of Sun Yat-sen University.MATERIALS ： Twenty-four male SD rats （3-4 weeks of age, weighing 200-220 g） were used in this study （Certification number：2001A027）. METHODS： The experiments were carried out in Zhongshan Medical College of Sun Yat-sen University between December 2003 and December 2004. ① Twenty-four male SD rats randomized into three groups with 8 rats in each： experimental group, control group and sham-operated group. Rats in the experiment al group and control group were induced into models of middle cerebral artery occlusion （MCAO）. After in vitro cultured, purified and identified with digestion, the Fischer344 rMSCs were induced to differentiate by tanshinone IIA, which was locally injected into the striate cortex （18 area） of rats in the experimental group, and the rats in the control group were injected by L-DMEM basic culture media （without serum） of the same volume to the corresponding brain area. In the sham-operated group, only muscle and vessel of neck were separated. ② At 2 and 8 weeks after the transplantation, the rats were given the screen test, prehensile-traction test, balance beam test and Morris water-maze test. ③ The survival and distribution of the induced cells in corresponding brain area were observed with Nissl stained with toluidine blue and hematoxylin and eosin （HE） staining in the groups.MAIN OUTCOME MEASURES ： ① Results of the behavioral tests （time of the Morris water-maze test screen test, prehensile-traction test, balance beam test）; ② Survival and distribution of the induced cells.RESULTS： All the 24 rats were involved in the analysis of results. ① Two weeks after transplantation, rats with neuron-like cells grafts in the experimental group had significant improvement on their general muscle strength than those in the control group [screen test： （9.4±1.7）, （4.7±1.0） s, P 〈 0.01]; forelimb muscle strength [prehensile-traction test： （7.6±1.4）, （5.2±1.2） s, P 〈 0.01], ability to keep balance [balance beam test： （7.9±0.74）, （6.1±0.91） s, P 〈 0.01] and abilities of learning and memory [latency to find the platform： （35.8±5.9）, （117.5±11.6） s, P 〈 0.01; distance： （623.1±43.4）, （1 902.3±98.6） cm, P 〈 0.01] as compared with those in the control group. The functional performances in the experimental group at 8 weeks were better than those at two weeks, which were still obviously different from those in the sham-operated group （P 〈 0.05）. ② The HE and Nissl stained brain tissue section showed that there was nerve cell proliferation at the infarcted cortex in the experiment group, the density was higher than that in the control group, plenty of aggregative or scattered cells could be observed at the site where needle was inserted for transplantation, the cells migrated directively towards the area around them, the cerebral vascular walls were wrapped by plenty of cells; In the control group, most of the cortices were destroyed, karyopyknosis and necrosis of neurons were observed, normal nervous tissue structure disappeared induced by edema, only some nerve fibers and glial cells remained.CONCLUSION： The rMSCs transplantation can obviously enhance the motor function and the abilities of learning and memory in rat models of cerebral infarction.

Correlation between special brain area and blood perfusion in patients with cerebral infarction at convalescent period Feasibility for quantitative determination and estimation of learning and memory function

BACKGROUND： Presently, clinic memory scale is used to evaluate learning memory ability in most studies, and the influence of difference in measurement condition of individuals exists. OBJECTIVE： To study the correlation between regional cerebral blood flow （rCBF） perfusion and learning memory function in special brain regions of patients with cerebral infarction at convalescent period, and to try to find out a method which can quantitatively evaluate learning ability. DESIGN： Case observation, and correlation analysis. SETTINGS： Shandong Institute for Behavioral Medicine; the Affiliated Hospital of Jining Medical College. PARTICIPANTS： Totally 70 patients with cerebral infarction admitted to Department of Neurology, Jining Medical College between January 2004 and December 2005 were involved. The involved patients, 58 male and 12 female, were averaged （52±3） years, and they were all right handed. They all met the diagnosis criteria instituted by the Fourth National Conference on Cerebrovascular Disease, and were confirmed as cerebral infarction by skull CT or MRI. Informed consents of detected items were obtained from all the patients and relatives. METHODS： When the patients were at convalescent period, their learning and memory ability were measured with “ clinic memory scale （set A）”. The 18 patients whose total mark over 100 were regarded as good learning memory function group; The 23 cases whose total mark less than 70 were regarded as poor learning memory function group. RCBF of hippocampus, nucleus amygdalae, temporal cortex and prefrontal lobe of patients between two groups were measured and compared by single photon emission computed tomography （SPECT）. The total scores of the 18 good learning memory patients and 23 poor learning memory patients were taken as dependent variable Y, and their rCBFs of hippocampus, nucleus amygdale, temporal cortex and prefrontal lobe respectively as independent variable X for linear correlation analysis. MAIN OUTCOME MEASURES： Correlation of rCBF in different brain regions and learning memory ability in patients with cerebral infarction. RESULTS： ①The rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex of good learning memory function group were significantly higher than those of poor learning memory function group （P 〈 0.05）. ②In the good learning memory function group, rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex were significantly positively correlated with memory scale scores （ r = 0.961, 0.926, 0.954, 0.907, P 〈 0.05 ） , and also in the poor learning memory function group （r = 0.979, 0.976, 0.991, 0.953, P 〈 0.05 ） . CONCLUSION： The rCBF of hippocampus, nucleus amygdale, temportal cortex and prefrontal cortex of patients with cerebral infarction are significantly positively correlated with memory scale scores. Predicting learning memory ability of patients by quantitative determination of rCBF provides a quantitative and objective method for evaluating learning memory ability.

DL-3-n-butylphthalide improved physical and learning and memory performance of rodents exposed to acute and chronic hypobaric hypoxia

Background:Studies have revealed the protective effect of DL-3-n-butylphthalide(NBP)against diseases associated with ischemic hypoxia.However,the role of NBP in animals with hypobaric hypoxia has not been elucidated.This study investigated the effects of NBP on rodents with acute and chronic hypobaric hypoxia.Methods:Sprague-Dwaley rats and Kunming mice administered with NBP(0,60,120,and 240 mg/kg for rats and 0,90,180,and 360 mg/kg for mice)were placed in a hypobaric hypoxia chamber at 10,000 m and the survival percentages at 30 min were determined.Then,the time and distance to exhaustion of drug-treated rodents were evaluated during treadmill running and motor-driven wheel-track treadmill experiments,conducted at 5800 m for 3 days or 20 days,to evaluate changes in physical functions.The frequency of active escapes and duration of active escapes were also determined for rats in a shuttle-box experiment,conducted at 5800 m for 6 days or 27 days,to evaluate changes in learning and memory function.ATP levels were measured in the gastrocnemius muscle and malonaldehyde(MDA),superoxide dismutase(SOD),hydrogen peroxide(H_(2)O_(2)),glutathione peroxidase(GSH-Px),and lactate were detected in sera of rats,and routine blood tests were also performed.Results:Survival analysis at 10,000 m indicated NBP could improve hypoxia tolerance ability.The time and distance to exhaustion for mice(NBP,90 mg/kg)and time to exhaustion for rats(NBP,120 and 240 mg/kg)significantly increased under conditions of acute hypoxia compared with control group.NBP treatment also significantly increased the time to exhaustion for rats when exposed to chronic hypoxia.Moreover,240 mg/kg NBP significantly increased the frequency of active escapes under conditions of acute hypoxia.Furthermore,the levels of MDA and H_(2)O_(2) decreased but those of SOD and GSH-Px in the sera of rats increased under conditions of acute and chronic hypoxia.Additionally,ATP levels in the gastrocnemius muscle significantly increased,while lactate levels in sera significantly decreased.Conclusion:NBP improved physical and learning and memory functions in rodents exposed to acute or chronic hypobaric hypoxia by increasing their anti-oxidative capacity and energy supply.

Tongdu Tiaoshen Acupuncture Method for Promoting Hippocampal Nerve Repair and Regeneration and Improving Learning and Memory Dysfunction in Stroke Model Rats

[Objectives]To evaluate the effects of Tongdu Tiaoshen Acupuncture method on improving learning and memory function and hippocampal nerve regeneration and repair after stroke.[Methods]Animal models of cognitive impairment in the recovery phase of cerebral infarction in rats were prepared,and rats were randomly divided into control group,model group,donepezil group,and acupuncture group.Morris water maze experiment was carried out to evaluate learning and memory ability.Nissl staining,BrdU and DCX immunofluorescence staining were used to observe the number and morphological structure of neuronal pyramidal and granular cells in the dentate gyrus(DG)area of the hippocampus,as well as the proliferation and differentiation of neural progenitor cells.TUNEL method was used to detect cell apoptosis.[Results]Before intervention,the scores and ELP of the model group,donepezil group and acupuncture group were significantly higher than those of the blank group(P<0.05);after the intervention,the neurological scores and ELP of the blank group and the model group were not significantly different from those before the intervention(P<0.05);the donepezil group and acupuncture group were significantly reduced,there was no difference between the donepezil group and acupuncture group(P>0.05),but it was still significantly higher than the blank group(P<0.05).The results of BrdU and DCX immunofluorescence staining showed that there were only a few BrdU positive cells and DCX protein in the hippocampal DG area of mice in the blank group,and the positive cells in the model group were significantly increased(P<0.05);donepezil group and acupuncture group showed significant increase compared with the model group(P<0.05);compared with the blank group,the number of neurons in the hippocampal DG area of each group was significantly reduced(P<0.01),and the neuronal apoptosis index was significantly increased(P<0.01);compared with the blank group,the number of neurons in the hippocampal DG area of each group was significantly reduced(P<0.01),and the neuronal apoptosis index was significantly increased(P<0.01).The number of neurons in the hippocampal DG area of rats in the acupuncture group and donepezil group was significantly increased(P<0.01),and the neuronal apoptosis index was significantly decreased(P<0.01).[Conclusions]Tongdu Tiaoshen Acupuncture method can improve the learning and memory function of stroke model rats by promoting the regeneration and repair of hippocampal nerve in rats with cerebral infarction.

Thalamic mechanism of learning and memory

The role of the thalamus in highlevel cognitive function such as learning and memory remains poorly understood.Here we systematically examined the role of paraventricular thalamus(PVT) in associative learning.We trained mice with olfactory conditioning task in which different olfactory cues were associated with different outcomes includes reward,punishment or nothing.Both fiber photometry and single-unit recordings revealed that PVT were robustly activated by a variety of behaviorally significant events including reinforcing stimuli and their predicting cues,as well as omission of the expected reward.PVT responses are proportional to the stimulus intensity and modulated by changes in homeostatic state or behavioral context.Optogenetic inhibition of the PVT responses suppresses appetitive or aversive associative learning and reward extinction.Our findings demonstrate that the PVT gates associative learning by providing a dynamic representation of stimulus salience.

Effects of repetitive transcranial magnetic stimulation on cognitive function and cholinergic activity in the rat hippocampus after vascular dementia

Repetitive transcranial magnetic stimulation （rTMS） is a non-invasive treatment that can enhance the recovery of neurological function after stroke. Whether it can similarly promote the recovery of cognitive function after vascular dementia remains unknown, In this study, a rat model for vascular dementia was established by the two-vessel occlusion method. Two days after injury, 30 pulses of rTMS were ad- ministered to each cerebral hemisphere at a frequency of 0.5 Hz and a magnetic field intensity of 1,33 T. The Morris water maze test was used to evaluate learning and memory function. The Karnovsky-Roots method was performed to determine the density of cholinergic neurons in the hippocampal CA1 region. Immunohistochemical staining was used to determine the number of brain-derived neurotroph- ic factor （BDNF）-immunoreactive cells in the hippocampal CA1 region, rTMS treatment for 30 days significantly improved learning and memory function, increased acetylcholinesterase and choline acetyltransferase activity, increased the density of cholinergic neurons, and increased the number of BDNF-immunoreactive cells. These results indicate that rTMS can ameliorate learning and memory deficiencies in rats with vascular dementia, The mechanism through which this occurs might be related to the promotion of BDNF expression and subsequent restoration of cholinergic system activity in hippocampal CA 1 region.

Effects of task orientation on subsequent source memory as revealed by functional MRI

Episodic memories are composed of various interrelated elements, including those specific to items of central interest and those pertaining to related features, such as the color, shape, size, spatial location, temporal order, and media or modalities of presentation. Memory about a core item （such as a word, object, or picture） is called item memory while memory about the context or related fea- tures of a core item is defined as source memory. What determines which sources within an episode are successfully remembered is of particular interest to researchers. Behavioral evidence suggests that the orientation of a memory task influences whether the related source of the item will be re- membered later. This study explored changes in the hippocampus and prefrontal cortex while par- ticipants completed two tasks： an item-oriented task and a source-oriented task. We used functional MRI to investigate the neural mechanisms by which task orientation influences source encoding. We found that subsequent source memory effects in the right prefrontal cortex and hippocampus were modulated by task orientation, whereas task orientation modulated item memory effects in the prefrontal cortex. These findings highlight the possibility that the hippocampus contributes to the intentional encoding of item-source associations, whereas the prefrontal cortex is biased toward processing information to which attention is directed.

The potential of endogenous neurogenesis for brain repair and regeneration following traumatic brain injury

Traumatic brain injury （TBI） is the leading cause of death and disability of persons under 45 years old in the United States, affecting over 1.5 million individtials each year. It had been th ought that recovery from such injuries is severely limited due to the inability of the adult bra in to replace damaged neurons. However, recent studies indicate that the mature mammalian central nervous system （CNS） has the potential to replenish damaged neurons by proliferation and neuronal differentiation of adult neural stem/progenitor cells residing in the neurogenic regions in the brain. Furthermore, increasing evidence indicates that these endogenous stem/ progenitor cells may play regenerative and reparative roles in response to CNS injuries or diseases. In support of this notion, heightened levels of cell proliferation and neurogenesis have been ob- served in response to brain trauma or insults suggesting that the brain has the inherent potential to restore populations of damaged or destroyed neurons. This review will discuss the potential functions of adult neurogenesis and recent development of strategies aiming at harnessing this neurogenic capacity in order to repopulate and repair the injured brain.

Application of modern neuroimaging technology in the diagnosis and study of Alzheimer’s disease

Neurological abnormalities identified via neuroimaging are common in patients with Alzheimer’s disease.However,it is not yet possible to easily detect these abnormalities using head computed tomography in the early stages of the disease.In this review,we evaluated the ways in which modern imaging techniques such as positron emission computed tomography,single photon emission tomography,magnetic resonance spectrum imaging,structural magnetic resonance imaging,magnetic resonance diffusion tensor imaging,magnetic resonance perfusion weighted imaging,magnetic resonance sensitive weighted imaging,and functional magnetic resonance imaging have revealed specific changes not only in brain structure,but also in brain function in Alzheimer’s disease patients.The reviewed literature indicated that decreased fluorodeoxyglucose metabolism in the temporal and parietal lobes of Alzheimer’s disease patients is frequently observed via positron emission computed tomography.Furthermore,patients with Alzheimer’s disease often show a decreased N-acetylaspartic acid/creatine ratio and an increased myoinositol/creatine ratio revealed via magnetic resonance imaging.Atrophy of the entorhinal cortex,hippocampus,and posterior cingulate gyrus can be detected early using structural magnetic resonance imaging.Magnetic resonance sensitive weighted imaging can show small bleeds and abnormal iron metabolism.Task-related functional magnetic resonance imaging can display brain function activity through cerebral blood oxygenation.Resting functional magnetic resonance imaging can display the functional connection between brain neural networks.These are helpful for the differential diagnosis and experimental study of Alzheimer’s disease,and are valuable for exploring the pathogenesis of Alzheimer’s disease.

基于EOF和LSTM的广西月降水量预测模型研究

针对夏季降水天气过程具有时间相关性和非线性变化的特点,以及现有预报方法未能充分获取月降水量的本质特征而造成的建模因子处理和预报建模困难等问题,提出了一种以自然正交展开(EOF)与深度学习长短期记忆神经网络(LSTM)相结合的月降水量预测模型。以广西81个气象观测站7月降水量为预报研究对象,对81站7月降水量作EOF计算,选取累积方差贡献超过76%的前7个主分量作为预报分量,再利用LSTM模型建立月降水量的深度学习预测模型,以1960—2016年81站7月降水量为建模样本,2017—2022年为独立样本进行建模研究。结果表明,在相同的预报建模样本和相同的预报因子条件下,新建立的预测模型比线性逐步回归预报方法有更高的预报能力,显示了对非线性月降水量预测问题的适用性。由于LSTM模型隐层里引入了存储单元状态和门结构,使得网络能够保留长期的状态,更适合于处理和预测时间序列中间隔和延迟相对较长的重要问题。

Effects of Bushen Huoxue Formula on the Learning and Memory Function and the Cerebral Neurotransmitters in Diabetic Mice

Objective: To observe the effects of Bushen Huoxue Formula (Formula for reinforcing the kidney and activating blood circulation) on the learning and memory function and the cerebral neurotransmitters in diabetic mice. Methods: Forty ICR mice were randomized into the normal control group, model group, Nimotop group and Chinese medicine group, 10 mice in each group. Tail intravenous injection of alloxan was applied to prepare diabetic model. Four weeks later, intragastric administration of Bushen Huoxue Formula for the Chinese medicine group, Nimotop for the Nimotop group, and isometric distilled water for the other two groups were respectively given for 8 weeks. The changes in the blood sugar level were observed; the learning and memory function was detected by Morris labyrinth test; and the contents of norepinephrine (NE), dopamine (DA), 5-hydroxyltryptamine (5-HT) and 5-hydroxyl indole acetic acid (5-HIAA) in cerebral cortex were determined in mice of all the groups. Results: The blood sugar levels in the diabetic model mice significantly increased as compared with those of the normal control group determined 72 h and 12 weeks later (P<0.05 or P<0.01). Latencies for Morris labyrinth test in the Nimotop group and the Chinese medicine group were significantly shortened as compared with that in the model group (P<0.01). The contents of cortical NE in the Chinese medicine group was significantly higher than that in the model group (P<0.01). Conclusion: Bushen Huoxue Formula can improve the learning and memory function in the diabetic mice, and the mechanism is possibly related with change of the cortical NE content.

Effect of Cistanche Desertica Polysaccharides on Learning and Memory Functions and Ultrastructure of Cerebral Neurons in Experimental Aging Mice

To observe the effects of Cistanche desertica polysaccharides (CDP) on the learning and memory functions and cerebral ultrastructure in experimental aging mice. Methods: CDP was administrated intragastrically 50 or 100 mg/kg per day for 64 successive days to experimental aging model mice induced by D-galactose, then the learning and memory functions of mice were estimated by step-down test and Y-maze test; organelles of brain tissue and cerebral ultrastructure were observed by transmission electron microscope and physical strength was determined by swimming test. Results: CDP could obviously enhance the learning and memory functions (P＜0.01) and prolong the swimming time (P＜0.05), decrease the number of lipofuscin and slow down the degeneration of mitochondria in neurons(P＜0.05), and improve the degeneration of cerebral ultra-structure in aging mice. Conclusion: CDP could improve the impaired physiological function and alleviate cerebral morphological change in experimental aging mice.

Effects of special brain area regional cerebral blood flow abnormal perfusion on learning and memory function and its molecular mechanism in rats

To study the effect of special brain area regional cerebral blood flow(rCBF)abnormal perfusion on learning and memory function and its molecular mechanism,64 adult male healthy Sprague-Dawley(SD)rats were randomly divided into two groups,the false operation group(control group)and the operation group(model group).After surgical operation,the operation group undertook bilateral common carotid artery permanent ligation,while the other group did not.Learning and memory function were measured by Y-maze at 4 h,8 h,24 h and 3 d after surgical operation,respectively.The rCBF of the right frontal lobe and hippocampus was also detected by the PerifluxPF model laser Doppler flowmetry,and the expressions of c-fos or c-jun or Bcl-2 and Bax were also measured by immune histochemistry S-P method accordingly.Results showed that the rCBF of the right frontal lobe and hippocampus in the operation group was significantly lower than that in the false operation group(P,0.05).The learning indexes,error number(EN),day of reach standard and total reaction time(TRT)in the operation group,were significantly higher than that in the false operation group(P,0.05).However,the initiative evasion rate in the operation group was significantly lower than that in the false operation group.The study also found that the rCBF was relatively more,the indexes(EN,the day of reach standard and TRT)relatively fewer,but the initiative evasion rate and the memory keeping rate were relatively more.The positive expression and the average absorbency of Fos and Jun in the operation group were significantly higher than that in the false operation group(P<0.05).Furthermore,Bax and Bcl-2 positive cells were all increased over time in the operation group,and the expression ratio of Bax/Bcl-2 in the operation group was significantly higher than that in the false operation group(P<0.01).In conclusion,rCBF decrease can impair the learning and memory function in rats,which may be related to the increase of the expression ratio of c-fos or c-jun or Bcl-2 or Bax in the frontal cortex and hippocampus.

七氟烷后处理对脑缺血大鼠学习记忆功能和氧化应激反应的影响

目的观察七氟烷(Sevo)后处理对脑缺血再灌注损伤(CIRI)大鼠的学习记忆功能、神经功能及氧化应激反应的影响。方法选取SPF级健康雄性老年SD大鼠40只,随机分为4组,分别为假手术组(Sham组)、脑缺血再灌注模型组(CIRI组)、2%Sevo后处理组(2%Sevo组)、3%Sevo后处理组(3%Sevo组),每组10只。除Sham组外余下3组采用左颈总动脉夹闭闭塞法构建CIRI大鼠模型。在模型构建后后处理组分别吸入2%、3%Sevo 30 min,Sham组、CIRI组则自主呼吸30 min。恢复灌注24 h后,使用Garcia神经功能评分评估神经功能;恢复灌注72 h后,通过Morris水迷宫实验检测学习记忆能力;随后收集血清并处死大鼠,利用酶联免疫吸附(ELISA)实验检测大鼠血清中的乳酸脱氢酶(LDH)、肌酸磷酸激酶(CK)和超氧化物歧化酶(SOD)及丙二醛(MDA)的活性;收集大鼠缺血侧脑皮质组织,通过ELISA实验检测其中白细胞介素(IL)-1β、IL-6和IL-10浓度。结果恢复灌注24 h后,CIRI组Garcia评分为(9.932±0.349)分,显著低于Sham组,Sevo后处理组Garcia评分较CIRI组升高,其中2%Sevo组效果显著(P<0.05)。恢复灌注72 h后,CIRI组各时段逃避潜伏期显著高于Sham组,穿越平台次数亦显著低于Sham组,Sevo后处理各组各时段逃避潜伏期明显降低、穿越平台次数明显升高,其中2%Sevo浓度组表现明显,差异有统计学意义(P<0.05)。CIRI组大鼠血清LDH、CK、MDA和脑组织IL-1β、IL-6、IL-10水平分别为(614.89±76.48)U/L、(1369.52±218.03)U/L、(10.68±1.25)nmol/mL和(2.91±0.48)pg/mg、(2.89±0.69)pg/mg、(11.62±1.94)pg/mg,均显著高于Sham组,血清SOD水平为(89.15±6.12)U/mL,显著低于Sham组,差异均有统计学意义(P<0.05),Sevo后处理组各指标水平趋势与之相反,其中2%Sevo浓度效果显著,差异有统计学意义(P<0.05)。结论七氟烷后处理对CIRI大鼠有明显的脑部保护作用,降低氧化应激反应;并能提高大鼠的学习记忆能力,减轻神经功能损伤与脑内炎症反应,以2%Sevo浓度效果最显著。其疗效机制可能与其抗炎、抗氧化机制有关。

基于鼻黏膜-海马神经免疫机制探讨醒鼻凝胶滴鼻剂对变应性鼻炎大鼠的影响

目的基于鼻黏膜-海马神经免疫机制探讨醒鼻凝胶滴鼻剂对变应性鼻炎(AR)大鼠的影响。方法选择21日龄(PND21)SPF级SD大鼠40只,采用随机数字表法分为正常组、模型组、中药组、西药组,每组10只。除正常组外,其余3组均采用卵清蛋白(OVA)致敏的方法构建AR动物模型。造模成功后,正常组和模型组均给予生理盐水滴鼻(50μL/次),中药组给予醒鼻凝胶滴鼻剂滴鼻(50μL/次),西药组给予布地奈德鼻喷雾剂滴鼻(20μL/次),2次/d,连续治疗12 d。采用AR大鼠行为学评分标准对大鼠进行鼻炎行为学评分;采用Morris水迷宫实验评估大鼠学习记忆功能;采用酶联免疫吸附试验法(ELISA)检测血清免疫球蛋白E(IgE)、转化生长因子-β1(TGF-β1)含量;采用苏木精-伊红染色法(HE)观察鼻黏膜组织病理变化及嗜酸性粒细胞(EOS)计数;采用免疫组化法检测海马组织非受体酪氨酸激酶Fyn、P物质(SP)、血管活性肠肽(VIP)、神经肽Y(NPY)表达水平;采用实时聚合酶链式反应(RT-PCR)检测海马组织Fyn、SP、VIP、NPY mRNA转录水平。结果(1)鼻炎行为学评分:与正常组比较,模型组、中药组、西药组治疗前鼻炎行为学评分均明显更高(P<0.05);与模型组比较,中药组和西药组治疗后鼻炎行为学评分均明显更低(P<0.05)。与治疗前比较,中药组和模型组治疗后鼻炎行为学评分均明显更低(P<0.05)。(2)学习记忆功能:与正常组比较,模型组平台潜伏期、游泳总路程均明显更长(P<0.05),穿越平台次数、目标象限停留时间均明显更低(P<0.05);与模型组比较,中药组和西药组治疗后平台潜伏期和游泳总路程均明显更短(P<0.05),穿越平台次数、目标象限停留时间均明显更高(P<0.05)。(3)血清IgE、TGF-β1含量:与正常组比较,模型组血清IgE、TGF-β1含量均明显更高(P<0.05);与模型组比较,中药组和西药组治疗后血清IgE、TGF-β1含量均明显更低(P<0.05)。(4)鼻黏膜组织病理变化及EOS计数:模型组鼻黏膜水肿,上皮细胞排列紊乱;中药组和西药组治疗后鼻黏膜水肿明显减轻,上皮细胞结构较完整。与正常组比较,模型组、中药组、西药组治疗后大鼠鼻黏膜EOS计数均明显增多(P<0.05);与模型组比较,中药组和西药组治疗后鼻黏膜EOS计数均明显减少(P<0.05)。(5)海马组织Fyn、SP、VIP、NPY mRNA转录水平和蛋白表达水平:与正常组比较,模型组海马组织Fyn、SP、VIP mRNA转录水平和Fyn、SP、VIP平均OD值均明显升高(P<0.05),NPY mRNA转录水平和NPY平均OD值均明显降低(P<0.05)。与模型组比较,中药组和西药组治疗后海马组织Fyn、SP、VIP mRNA转录水平和Fyn、SP、VIP平均OD值均明显降低(P<0.05),NPY mRNA转录水平和NPY平均OD值均明显升高(P<0.05)。结论醒鼻凝胶滴鼻剂可改善AR大鼠鼻炎行为学和学习记忆功能,可能与通过Fyn信号通路调节鼻黏膜-海马神经免疫机制有关。

Effects of regional cerebral blood flow perfusion on learning and memory function and its molecular mechanism in rats

Objective:To study the effects of regional cerebral blood flow(r CBF)perfusion on learning and memory function in special brain areas and its molecular mechanism in rat.Methods:Sixty-four adult male healthy Sprague-Dawley(SD)rats were randomly divided into two groups:A false operation group and an operation group.The false operation group was randomly divided into four subgroups(A_0,B_0,C_0,and D_0)and the operation group was randomly divided into four subgroups(A,B,C,and D),with eight rats in each subgroup.The operation group underwent bilateral common carotid artery permanent ligation,while the other group only underwent a skin incision without the bilateral common carotid artery permanent ligation.Learning memory function of rats in each subgroup was measured using a Y-maze at 4 h,8 h,24 h,and 3 days after surgery.The r CBF in the right frontal lobe and hippocampus was detected using the Periflux PF model laser Doppler flowmetry and c-fos,c-jun,Bcl-2,and Bax protein expression in the right frontal lobe and hippocampus was measured using immunohistochemistry.Results:The r CBF in the right frontal lobule division and right hippocampus division was significantly lower in the operation group than in the false operation group(P<0.05).The error number(EN),time to reach the target,and total reaction time(TRT)for the learning index using the Y-type labyrinth test in the operation group were significantly higher than that in the false operation group(P<0.05);however,the active avoid rate in the operation group was significantly lower than that of the false operation group.Expression of c-fos and c-jun as well as the average absorbency in the right frontal lobule division and right hippocampus division in the operation group were significantly higher than those in the false operation group(P<0.05).The number of Bax and Bcl-2-positive cells was significantly higher in the operation group,and the expression ratio of Bax/Bcl-2 in the operation group was significantly higher than that in the false operation group(P<0.01).Conclusions:r CBF decrease can impair learning and memory function in rats,which may be related to the increased expression of c-fos,c-jun,Bcl-2,and Bax proteins in the frontal cortex and hippocampus.

全身麻醉对行卵巢囊肿手术的围绝经期患者RBMT-Ⅲ评分及神经功能性因子水平的影响

目的探讨全身麻醉对行卵巢囊肿手术的围绝经期患者Rivermead行为记忆测验第3版(RBMT-Ⅲ)评分及神经功能性因子水平的影响。方法采用前瞻性研究方法,选取2021年1月至2023年4月在广州医科大学附属第三医院行卵巢囊肿手术的围绝经期患者92例作为观察组,同时选取行卵巢囊肿手术的非围绝经期患者92例作为对照组,两组均接受全身麻醉和卵巢囊肿腹腔镜手术治疗。观察两组手术时间、麻醉时间、气腹时间和苏醒时间以及麻醉诱导前、插管后、气腹建立后和苏醒时心率、平均动脉压(MAP)和血氧饱和度(SpO_(2)),以及麻醉前、麻醉后3 d两组患者RBMT-Ⅲ总分和神经功能性因子[血清S100钙结合蛋白B(S100B)、5-羟色胺(5-HT)、γ-氨基丁酸(GABA)和脑源性神经营养因子(BDNF)]水平。结果观察组和对照组手术时间、麻醉时间、气腹时间和苏醒时间比较,差异均无统计学意义(P>0.05);两组插管后、气腹建立后和苏醒时心率较麻醉诱导前均降低,两组插管后、气腹建立后MAP较麻醉诱导前均降低,差异均有统计学意义(P<0.05),两组插管后、气腹建立后和苏醒时SpO_(2)与麻醉诱导前比较,组内差异均无统计学意义(P>0.05)。两组麻醉诱导前、插管后、气腹建立后和苏醒时心率、MAP和SpO_(2)组间比较,差异均无统计学意义(P>0.05)。麻醉后3 d,观察组RBMT-Ⅲ总分为(71.65±10.41)分,明显低于对照组[(92.24±9.97)分],差异有统计学意义(P<0.05)。麻醉后3 d,观察组的S100B水平为(0.68±0.11)ng/mL,明显高于对照组[(0.55±0.12)ng/mL],差异有统计学意义(P<0.05);两组5-HT、GABA和BDNF水平比较,差异均无统计学意义(P>0.05)。结论相比较卵巢囊肿手术的非围绝经期患者,全身麻醉对围绝经期患者术后记忆功能及神经功能性因子S100B有明显影响,应更加注重围手术期麻醉管理。

钩藤降压解郁方对高血压并发抑郁症大鼠学习记忆能力及海马自噬相关蛋白表达的影响

目的研究钩藤降压解郁方(钩藤、天麻、地龙、葛根、丹参等)对高血压并发抑郁症(Hypertension complicated with depression,HD)大鼠学习记忆能力、海马炎症反应和自噬相关蛋白表达的影响。方法将30只自发性高血压大鼠(SHR)随机分为模型组、阳性对照组(苯磺酸左旋氨氯地平0.45 mg·kg^(-1)+盐酸氟西汀1.80 mg·kg^(-1))及钩藤降压解郁方高、中、低剂量组(25.38、12.69、6.34 g·kg^(-1)),另取6只SD大鼠作空白对照组。采用慢性温和不可预见性应激联合孤养的方法干预SHR大鼠,复制HD大鼠模型。造模同时灌胃给药,每天1次,连续6周。采用无创血压计测量大鼠尾动脉收缩压(SBP)和舒张压(DBP);通过Morris水迷宫实验检测大鼠学习记忆能力;透射电镜观察大鼠海马神经元超微结构;ELISA法检测海马组织中白细胞介素1β(IL-1β)、IL-18及IL-10含量;免疫组化法检测海马组织中自噬相关蛋白Beclin1、Bcl-2的表达;Western Blot法检测海马组织中自噬相关蛋白LC3Ⅰ、LC3Ⅱ的表达。结果与空白对照组比较,模型组大鼠第1~6周的SBP、DBP均显著升高(P<0.01);第3、4天的逃避潜伏期显著延长(P<0.01);第1次穿越平台区时间显著延长(P<0.01),穿越平台区次数明显减少(P<0.05),平台区滞留时间显著缩短(P<0.01);海马神经元胞体明显肿胀,嵴破坏,细胞核皱缩,出现大量自噬小体;海马组织中IL-1β、IL-18含量显著增加(P<0.01);海马组织中LC3Ⅱ/LC3Ⅰ蛋白表达比值和Beclin1蛋白表达明显上调(P<0.05,P<0.01),Bcl-2蛋白表达显著下调(P<0.01)。与模型组比较,钩藤降压解郁方低剂量组大鼠第1、3、4、5、6周的SBP显著降低(P<0.01),第1、3、4、5周的DBP明显降低(P<0.05,P<0.01);钩藤降压解郁方中剂量组大鼠第1、5、6周的SBP显著降低(P<0.01),第4周的DBP明显降低(P<0.05);钩藤降压解郁方高剂量组大鼠第1周的SBP显著降低(P<0.01)。钩藤降压解郁方高、中剂量组大鼠第3天的逃避潜伏期明显缩短(P<0.05),钩藤降压解郁方高、低剂量组大鼠第4天的逃避潜伏期明显缩短(P<0.05)。钩藤降压解郁方高、中、低剂量组大鼠第1次穿越平台区时间显著缩短(P<0.01),钩藤降压解郁方中、低剂量组大鼠穿越平台区次数明显增加(P<0.05),平台区滞留时间明显延长(P<0.05)。给药组海马神经元损伤程度减轻,细胞核皱缩情况明显改善,自噬小体减少。钩藤降压解郁方高、中剂量组大鼠海马组织中促炎因子IL-1β、IL-18含量显著降低(P<0.05,P<0.01),钩藤降压解郁方高剂量组大鼠海马组织中抗炎因子IL-10含量显著升高(P<0.01)。钩藤降压解郁方高、中、低剂量组海马组织中的LC3Ⅱ/LC3Ⅰ蛋白表达比值显著下调(P<0.01),Bcl-2蛋白表达显著上调(P<0.01);钩藤降压解郁方高、中剂量组大鼠海马组织中Beclin1蛋白表达明显下调(P<0.05,P<0.01)。结论钩藤降压解郁方可降低HD大鼠尾动脉压,改善其学习记忆能力,缓解海马神经元损伤,其机制可能与减少促炎因子释放,提高抗炎因子水平,调控海马自噬相关蛋白LC3Ⅱ/LC3Ⅰ、Beclin1和Bcl-2的表达有关。

十全大补汤通过调节突触功能对阿尔兹海默病小鼠认知损伤的改善作用

目的探究十全大补汤对阿尔兹海默病(AD)小鼠突触功能及认知损伤的改善作用。方法60只小鼠随机分为对照组、模型组、美金刚组(5 mg/kg)和十全大补汤高、中、低剂量组(6.24、3.12、1.56 g/kg),每组10只,除对照组外,其余各组小鼠腹腔注射D-半乳糖并灌胃AlCl370 d建立AD模型,造模第29天开始,各组灌胃给予相应剂量药物42 d。通过Morris水迷宫实验和条件恐惧实验检测空间学习记忆及联想记忆,HE染色观察海马神经元形态改变情况,试剂盒检测血清SOD活性、MDA水平及海马组织SOD、AChE活性,MDA、ACh、TNF-α、IL-1β水平,Western blot法检测海马组织PSD-95、Shank3、NR1、NR2A、NR2B、AMPK、p-AMPK蛋白表达。结果与模型组比较,十全大补汤高剂量组小鼠空间学习记忆能力与联想记忆提升(P<0.05,P<0.01),海马神经元病理损伤减轻,氧化应激及炎症水平下降(P<0.05,P<0.01),胆碱能传递增强(P<0.05,P<0.01),海马组织PSD-95、Shank3、NR1、NR2A、NR2B、p-AMPK蛋白表达升高(P<0.05,P<0.01)。结论十全大补汤可改善AD小鼠认知损伤,其机制可能与激活AMPK,恢复突触功能有关。