Cells In Hippocampal CA1 Region Research Articles

Effect of moxibustion on inositol requiring enzyme 1 / X-box binding protein 1 pathway in hippocampal CA1 region of rats with vascular dementia

To observe the effect of moxibustion at Governor Vessel acupoints on inositol requiring enzyme 1 （IRE1） / X-box binding protein 1 （XBP1） pathway in hippocampal CA1 region of rats with vascular dementia （VD）, so as to explore its mechanisms in the treatment of VD. Male SD rats were randomly divided into normal, sham operation, model, moxibustion （Moxi） and medication groups （n=12）. The VD model was established by permanent ligation of bilateral common carotid arteries. For rats of the Moxi group, mild moxibustion was given to "Baihui" （GV20）, "Dazhui" （GV14） and "Fengfu" （GV16） for 20 min each point, once a day for consecutive 6 days per week, for a total of 4 weeks. For rats of the medication group, intragastric perfusion of nimodipine was given 3 times each day with total dose of 2 mg•kg-1•d-1 for 4 weeks. Morris water maze test was used to detect the learning and memory ability of rats before and after modeling as well as after intervention. The apoptosis rate of nerve cells in hippocampal CA1 region was detected by TUNEL staining. The proteins and mRNA expression levels of IRE1, XBP1, B-cell lymphoma/leukemia-2 （Bcl-2）, Bcl-2 associated X protein （Bax） in hippocampal CA1 region were detected by Western blot and real-time quantitative PCR, respectively. Compared with the sham operation group, the average escape latency was significantly prolonged （P<0.01）, the number of times crossing the original platform was significantly reduced （P<0.01）, the apoptosis rate of nerve cells in hippocampal CA1 region was significantly increased （P<0.01）, the proteins and mRNA expression levels of IRE1, XBP1 and Bax were significantly increased （P<0.01）, and the expression levels of Bcl-2 protein and mRNA were significantly decreased （P<0.01） in rats of the model group. After treatment, compared with the model group, the average escape latency was significantly shortened （P<0.01）, the number of times crossing the original platform was increased （P<0.05）, the apoptosis rate of nerve cells in hippocampal CA1 region was significantly decreased （P<0.01）, the protein and mRNA expression levels of IRE1, XBP1 and Bax were decreased （P<0.05, P<0.01）, and the expression levels of Bcl-2 protein and mRNA were increased （P<0.05, P<0.01） in rats of the Moxi group and medication group. There was no significant difference in the above indexes between the Moxi group and the medication group. Moxibustion at the acupoints of Governor Vessel can improve the cognitive function of VD rats, and its mechanism may be related to regulating IRE1/XBP1 pathway, inhibiting the release of pro-apoptotic protein Bax, increasing the expression of anti-apoptotic protein Bcl-2, and thus inhibiting the apoptosis of hippocampal nerve cells.

Effect of electroacupuncture on hippocampal synaptic plasticity and complement dependent memory impairment in Parkinson's disease dementia mice

To observe the effect of electroacupuncture (EA) of "Xiusanzhen" ［bilateral "Yingxiang"(LI20)+"Yintang"(GV24+)］ on synaptophysin (SYN), postsynaptic density protein-95 (PSD-95), Iba-1+ CD68+ microglia and complement C related protein expression of hippocampus in Parkinson's disease dementia (PDD) mice, so as to explore its mechanism in improving memory impairment of PDD. Male C57BL/6 mice were randomly divided into control, sham operation, model and EA groups, with 10 mice in each group. The PDD model was established by injecting 6-OHDA into the medial forebrain tract. EA (2 Hz, 1 mA) was applied to unilateral LI20 and GV29 for 20 min once daily for consecutive 14 days. Morris water maze and new object recognition test were used to evaluate the learning and memory ability. Western blot was used to detect the expression of SYN and PSD-95 proteins in hippocampus. Immunofluorescence was used to label Iba-1+ CD68+ microglia and C1q positive cells in hippocampal CA1 region. The content of C3 protein in hippocampus was detected by ELISA. Compared with the control group, there was no statistical significance in all the observed indexes in the sham operation group. Compared with the sham operation group, the average escape latency (AEL) prolonged significantly (P<0.01), the target platform crossing times (TPCT) and new object recognition index (NORI) decreased remarkably (P<0.01); the expressions of SYN and PSD-95 proteins in hippocampal CA1 region were significantly decreased (P<0.01); the rate of Iba-1+CD68+ microglia, the rate of C1q positive cells and the content of C3 protein were significantly increased (P<0.01) in the model group. In comparison with the model group, the AEL was shortened (P<0.01), the TPCT and NORI were increased (P<0.05) remarkably; the expressions of SYN and PSD-95 proteins in hippocampal CA1 region were increased (P<0.01, P<0.05); the rate of Iba-1+ CD68+ microglia, the rate of C1q positive cells and the content of C3 protein were significantly decreased (P<0.01) in the EA group. "Xiusanzhen" can alleviate the learning and memory impairment of PDD model mice, and improve the synaptic plasticity of hippocampal CA1 area. The mechanism may be related to the reduction of C1q and C3 deposition in hippocampal CA1 region and the reduction of microglia phagocytosis.

Inhibition of oxidative stress by testosterone improves synaptic plasticity in senescence accelerated mice

ABSTRACTIt is well known that synaptic plasticity is associated with cognitive performance in Alzheimer’s disease (AD). Testosterone (T) is known to exert protective effects on cognitive deficits in AD, but the underlying mechanisms of androgenic action on synaptic plasticity remain unclear. Thus, the aim of this study was to examine the protective mechanism attributed to T on synaptic plasticity in an AD senescence accelerated mouse prone 8 (SAMP8) model. The following parameters were measured: (1) number of intact pyramidal cells in hippocampal CA1 region (2) phosphorylated N-methyl-D-aspartate receptor-1 (p-NMDAR1) and (3) phosphorylated calmodulin-dependent protein kinase II (p-CaMKII). In addition, the content of whole brain malondialdehyde (MDA) as well as activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined. Treatment with T significantly elevated the number of intact pyramidal cells in hippocampal CA1 region and markedly increased hippocampal protein and mRNA expression levels of p-NMDAR1 and p-CaMK II. Further, T significantly decreased whole brain MDA levels accompanied by elevated activities of SOD and GSH-Px. Data suggest that the protective effects of T on synaptic plasticity in a mouse AD model may be associated with reduction of oxidant stress.

Small Changes in Inter-Pulse-Intervals Can Cause Synchronized Neuronal Firing During High-Frequency Stimulations in Rat Hippocampus.

Deep brain stimulation (DBS) traditionally utilizes electrical pulse sequences with a constant frequency, i.e., constant inter-pulse-interval (IPI), to treat certain brain disorders in clinic. Stimulation sequences with varying frequency have been investigated recently to improve the efficacy of existing DBS therapy and to develop new treatments. However, the effects of such sequences are inconclusive. The present study tests the hypothesis that stimulations with varying IPI can generate neuronal activity markedly different from the activity induced by stimulations with constant IPI. And, the crucial factor causing the distinction is the relative differences in IPI lengths rather than the absolute lengths of IPI nor the average lengths of IPI. In rat experiments in vivo, responses of neuronal populations to applied stimulation sequences were collected during stimulations with both constant IPI (control) and random IPI. The stimulations were applied in the efferent fibers antidromically (in alveus) or in the afferent fibers orthodromically (in Schaffer collaterals) of pyramidal cells, the principal cells of hippocampal CA1 region. Amplitudes and areas of population spike (PS) waveforms were used to evaluate the neuronal responses induced by different stimulation paradigms. During the periods of both antidromic and orthodromic high-frequency stimulation (HFS), the HFS with random IPI induced synchronous neuronal firing with large PS even if the lengths of random IPI were limited to a small range of 5–10 ms, corresponding to a frequency range 100–200 Hz. The large PS events did not appear during control stimulations with a constant frequency at 100, 200, or 130 Hz (i.e., the mean frequency of HFS with random IPI uniformly distributed within 5–10 ms). Presumably, nonlinear dynamics in neuronal responses to random IPI might cause the generation of synchronous firing under the situation without any long pauses in HFS sequences. The results indicate that stimulations with random IPI can generate salient impulses to brain tissues and modulate the synchronization of neuronal activity, thereby providing potential stimulation paradigms for extending DBS therapy in treating more brain diseases, such as disorders of consciousness and vegetative states.

The protective mechanism underlying phenylethanoid glycosides (PHG) actions on synaptic plasticity in rat Alzheimer’s disease model induced by beta amyloid 1-42

ABSTRACTPhenylethanoid glycosides (PHG), derived from Herba cistanche, were found to exert protective effects on cognitive dysfunctions by improving synaptic plasticity in Alzheimer’s disease (AD) rat model. However, the mechanisms underlying these effects of PHG on synaptic plasticity remain to be determined. Thus the aim of this study was to examine the influence of PHG on synaptic plasticity in male AD rat model induced by bilateral central nervous system ventricle injections of beta amyloid 1–42 oligomers (Aβ1–42). The following parameters were measured: (1) number of intact pyramidal cells in hippocampal CA1 region by Nissl staining, (2) post synaptic density 95 (PSD-95), phosphorylated N-methyl-D-aspartate receptor-1(p-NMDAR1) and (3) phosphorylated Tau protein (p-Tau) by immunohistochemistry and western blot. In addition, the content of malondialdehyde (MDA) and activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) were determined. Aβ1-42 lowered the number of intact pyramidal cells in hippocampal CA1 region. In contrast, treatment with PHG significantly elevated this cell number. Aβ1-42 significantly diminished protein expression levels of PSD-95 accompanied by elevated protein expression levels of p-NMDAR1 and p-Tau. PHG markedly increased protein expression levels of PSD-95, but significantly reduced protein expression levels of p-NMDAR1 and p-Tau. Further, Aβ1-42 markedly increased MDA content concomitantly with reduced activities of SOD and GSH-Px. PHG significantly decreased MDA content accompanied by elevated activities of SOD and GSH-Px. Data suggest that the protective effects of PHG on synaptic plasticity may involve inhibition of cytotoxicity-mediated by Aβ-1-42 administration and reduction of oxidant stress.

BDNF val66met Polymorphism Impairs Hippocampal Long-Term Depression by Down-Regulation of 5-HT3 Receptors.

Brain-derived neurotrophic factor (BDNF) is a key regulator of neuronal plasticity and cognitive functions. BDNF val66met polymorphism, a human single-nucleotide polymorphism (SNP) in the pro-domain of BDNF gene, is associated with deficits in activity-dependent BDNF secretion and hippocampus-dependent memory. However, the underlying mechanism remains unclear. Here we show that in the BDNFMet/Met mouse line mimicking the human SNP, BDNF expression in the hippocampus was decreased. There was a reduction in the total number of cells in hippocampal CA1 region, while hippocampal expression of mRNAs for NR2a, 2b, GluR1, 2 and GABAARβ3 subunits were up-regulated. Although basal glutamatergic neurotransmission was unaltered, hippocampal long-term depression (LTD) induced by low-frequency stimulation was impaired, which was partially rescued by exogenous application of BDNF. Interestingly, 5-HT3a receptors were down-regulated in the hippocampus of BDNFMet/Met mice, whereas 5-HT2c receptors were up-regulated. Moreover, impaired LTD in BDNFMet/Met mice was reversed by 5-HT3aR agonist. Thus, these observations indicate that BDNF val66met polymorphism changes hippocampal synaptic plasticity via down-regulation of 5-HT3a receptors, which may underlie cognition dysfunction of Met allele carriers.

Mesenchymal stem cell therapy for the streptozotocin-induced neurodegeneration in rats

Background and Aim: Bone marrow-derived mesenchymal stem cells (BM-MSCs) are one of the sources of adult stem cells being explored for potential use in repairing neurodegenerative disorders. In this study, it was aimed to investigate the useful effects of BM-MSCs therapy on the streptozotocin-induced neurodegeneration in rats.Materials and Methods: Adult female Wistar rats were bilaterally injected intra-cerebroventricularly with streptozotocin (3 mg/kg) for neurodegeneration. Water maze tests were used to monitor spatial learning and memory. One or two intravenous injections of BM-MSCs were administrated to rat via the tail veins. At the end of the study, all rats were sacrificed for histological evaluation and immunohistochemistry.Results: Streptozotocin group demonstrated a significant increase in escape latency in comparison with both control groups (Sham and Saline), whereas rats treated with BM-MSCs exhibited a decrease in escape latency in comparison with streptozotocin group. The percentage of time spent in the target quadrant and the mean number of platform crossings did not change in all the groups. BM-MSCs administration improved spatial learning but not memory. However, improvement in neuronal cells in hippocampal CA1 region was only observed in the rats treated with BM-MSCs twice as opposed to the rats treated with BM-MSCs once or with saline.Conclusions: In this study, mesenchymal stem cells therapy failed to improve the streptozotocin-induced neurodegeneration like Alzheimer’s disease in rats.

Therapeutic effect of bone marrow mesenchymal stem cells on cold stress induced changes in the hippocampus of rats.

The present study aims to evaluate the effect of bone marrow mesenchymal stem cells on cold stress induced neuronal changes in hippocampal CA1 region of Wistar rats. Bone marrow mesenchymal stem cells were isolated from a 6-week-old Wistar rat. Bone marrow from adult femora and tibia was collected and mesenchymal stem cells were cultured in minimal essential medium containing 10% heat-inactivated fetal bovine serum and were sub-cultured. Passage 3 cells were analyzed by flow cytometry for positive expression of CD44 and CD90 and negative expression of CD45. Once CD44 and CD90 positive expression was achieved, the cells were cultured again to 90% confluence for later experiments. Twenty-four rats aged 8 weeks old were randomly and evenly divided into normal control, cold water swim stress (cold stress), cold stress + PBS (intravenous infusion), and cold stress + bone marrow mesenchymal stem cells (1 × 106; intravenous infusion) groups. The total period of study was 60 days which included 1 month stress period followed by 1 month treatment. Behavioral functional test was performed during the entire study period. After treatment, rats were sacrificed for histological studies. Treatment with bone marrow mesenchymal stem cells significantly increased the number of neuronal cells in hippocampal CA1 region. Adult bone marrow mesenchymal stem cells injected by intravenous administration show potential therapeutic effects in cognitive decline associated with stress-related lesions.

The changes of brain-derived neurotrophic factor positive neurons and the morphology of pyramidal cells in hippocampal in sodium valproate induced autism rats

Objective To explore the pathogenesis of autism by observation of changes of brain-derived neurotrophic factor(BDNF) positive neurons and the morphology of pyramidal cells in hippocampal CA1 region, and provide theoretical evidence for the therapeutic schedule. Methods Animal model of autism was obtained by Schneider method.Using the immunohistochemistry methods and image analysis, the number of BDNF positive neurons was examined in hippocampal CA1 region of the autism model rats and the normal rats, and the changes of pyramidal cell were observed in hippocampal CA1 region after HE staining. Results The numbers of BDNF positive neurons in the hippocampal CA1 region of the autism model rats were more than those of the normal rats (5.00±1.60 vs 3.00±1.04, t=3.63, P=0.0015). The morphology of pyramidal cells showed that the pyramidal cells of the autism model rats in hippocampal CA1 region had apoptosis. Conclusion The occurrence of autism may be related to the changes of BDNF and the morphology of pyramidal cells in hippocampal CA1 region. Key words: Autism spectrum disorder; Brain-derived neurotrophic factor; Pyramidal cell; Rats

Effects of normobaric hyperoxia on the learning and memory abilities of valproic acid autism model rats and the morphology of pyramidal cells in hippocampal CA1 region

Objective To investigate the effects of normobaric hyperoxia intervention on learning and memory abilities of valproic acid(VPA) autism model rats and the morphology of pyramidal cells in hippocampus CA1 area. Methods Animal model groups of autism were obtained in male offspring of the Wistar rats that received intraperitoneal injection of 600 mg/kg VPA at the 12.5 day after pregnancy. According to the eye opening time, behavior, weaning weight and the learning and memory abilities which were evaluated by the Y electricity maze test at the 28th day after birth, 40 male VPA autism model rats were randomly selected 20 only and divided into normobaric hyperoxia model group(group A, n=10), atmospheric air model group(group B, n=10). Normal control groups were obtained in male offspring of Wistar rats that received intraperitoneal injection of equivalent physiological saline at the same period pregnancy.(group C, n=10). Rats in group A were treated with oxygen for 1h per day and lasted 1 week; group B and C were treated with normal air. The learning and memory abilities of three groups were assessed at the 35th day after birth. The immunohistochemistry methods and image analysis were used to observe the pyramidal cells of autism model rats in hippocampal CA1 region. The effect of normobaric hyperoxia therapy on pyramidal cell of autism model rats in hippocampal CA1 region were evaluated by HE staining technique. Results The trying times of group A after treatment were less than those before treatment (31.15±0.99 vs 31.54±0.97, t=2.739, P=0.018). The memory times were more than those before treatment(3.00±0.58 vs 2.69±0.48, t=-2.309, P=0.040). The trying times of group A after treatment were less than those in group B after treatment(P=0.016). The memory times of group A were not different from that in group B after treatment(P=0.810). The morphology of pyramidal cells in hippocampal CA1 region showed that the pyramidal cells of the autism model rats had apoptosised. The number of apoptotic cells reduced and the number of normal form cells increased after the normobaric hyperoxia intervention compared with the autism model rats. Conclusion Normobaric hyperoxia intervention can improve the learning and memory abilities of the autism model rats.The apoptosis of the pyramidal neurons in hippocampal CA1 might be reduced after the normobaric hyperoxia intervention. Key words: Valproate; Normobaric hyperoxia; Autism; Learning and memory; Hippocampus

Anti-amnesic effect of neurosteroid PREGS in Aβ25–35-injected mice through σ1 receptor- and α7nAChR-mediated neuroprotection

A single intracerebroventricular injection of β-amyloid 25–35 peptide (Aβ25–35) (9 nmol/mouse) induces the spatial cognitive deterioration and approximately 50% loss of pyramidal cells in hippocampal CA1 region within 1 week. The present study focused on exploring the effects of neurosteroid pregnenolone sulfate (PREGS), in comparison with the selective agonists of sigma-1 receptor (σ1R) and α7 nicotinic acetylcholine receptor (α7nAChR), on the cognitive deficits and the death of pyramidal cells in Aβ25–35-mice. Herein, we reported that the administration of PREGS (1–100 mg/kg) for 7 days after Aβ25–35-injection could dose-dependently ameliorate the cognitive deficits and attenuate the apoptosis of pyramidal cells. Either the σ1R antagonist NE100 or the α7nAChR antagonist MLA could block the neuroprotection of PREGS in Aβ25–35-mice. Both the σ1R agonist PRE084 and the α7nAChR agonist DMXB could mimic the PREGS-neuroprotection against the Aβ25–35-neurotoxicity. The neuroprotection of PRE084 was attenuated by MLA, but the DMXB-action was insensitive to NE100. The neuroprotection of PREGS, PRE084 or DMXB was blocked by the phosphatidylinositol-3-kinase (PI3K) inhibitor LY294002, whereas only the effect of PREGS or PRE084 was sensitive to the MAPK/ERK kinase (MEK) inhibitor U0126. PREGS prevented Aβ25–35-inhibited Akt (Serine/threonine kinase) phosphorylation leading to increase in caspase-3 activity, which was σ1R- and α7nAChR-dependent. By contrast, PREGS-rescued reduction of extracellular signal-related kinase-2 (ERK2) phosphorylation in Aβ25–35-mice only required the activation of σ1R. Blockage of PREGS-neuroprotection by LY294002 significantly attenuated its anti-amnesic effect in Aβ25–35-mice. The findings indicate that the anti-amnesic effects of PREGS in Aβ25–35-mice depend on the σ1R- and α7nAChR-mediated neuroprotection.

Long-term ginsenoside administration prevents memory loss in aged female C57BL/6J mice by modulating the redox status and up-regulating the plasticity-related proteins in hippocampus

Memory impairment is considered to be one of the most prominent consequences of aging. Deterioration of memory begins in advance of old age in animals, including humans. The generation of reactive oxygen species (ROS) and/or free radicals-induced oxidative stress which is the major age-related changes, can lead to hippocampus damage and increase vulnerability to impaired learning and memory. Ginsenoside, the effective ingredient of ginseng, has been reported to have a neuron beneficial effect. In the present study, C57BL/6J mice aged 12 months were chronically treated with ginsenoside (three dose groups were given ginsenoside in drinking water for 8 months, the concentration of ginsenoside in drinking water was 0.028%, 0.056%, and 0.112% (w/v), respectively). Placebo-treated aged mice and young ones (4 months old) were used as controls. The efficacious effect of ginsenoside was manifested in the amelioration of memory impairment in aged mice by Morris water maze and step-down tests. Total superoxide dismutase (T-SOD), glutathione peroxidase (GSH-Px), and thiobarbituric acid reactive substances (TBARS) have been used as the biomarkers of oxidative stress. In ginsenoside treated groups, the activities of T-SOD and GSH-Px markedly increased, and the levels of TBARS and the content of protein carbonyl decreased significantly in serum and in hippocampus. The activation of lipofuscin formation, disruption or loss of cristae in mitochondria, the irregular nucleus and condensed chromatin laid against the nuclear membrane in pyramidal cells of hippocampal CA1 region, which are all related to oxidative stress, were also reduced after ginsenoside treatment. Processes of memory formation and functional plasticity are associated with postsynaptic density-95 (PSD-95), protein kinase Cγ subunit (PKCγ) and brain derived neurotrophic factor (BDNF). In the present study, we found that long-term ginsenoside treatment prevented age-related reductions of PSD-95, PKCγ, and BDNF in the hippocampus. These results demonstrated that long-term ginsenoside administration may prevent memory loss in aged C57BL/6J mice by modulating the redox status and up-regulating the plasticity-related proteins in hippocampus.

Electroacupuncture Protected Pyramidal Cells in Hippocampal CA1 Region of Vascular Dementia Rats by Inhibiting the Expression of P53 and Noxa

Clinically electroacupuncture (EA) is proved an effective therapy for vascular dementia (VD), but their mechanisms remain uncertain. The aim of this study was to determine whether EA protects pyramidal cells from apoptosis in hippocampus of a VD rat model by inhibiting the expression of p53 and Noxa. One month after a VD animal model was established by bilateral occlusion of common carotid arteries, EA treatment was given at "Baihui" (DU20), "Dazhui" (DU14), and "Shenshu" (BL23). The learning and memory ability was assessed by Morris water maze. Neuronal apoptosis in hippocampus was evaluated with hematoxylin-eosin (HE) staining, and the expression of p53 and Noxa was analyzed by confocal laser scanning microscope with immunofluorescence staining. Expressions of p53 and Noxa in the EA group and sham-operated group were less than in the VD model group (P < 0.01), and the expression of p53 was positively correlated to expression of Noxa in hippocampus of VD rats (r = 0.918, P < 0.01). EA treatment could reduce the amount of apoptotic neurons in hippocampal CA1 area of rats with VD. The average latency in the Morris water maze test was significantly shorter, and escape strategies improved from edge and random searches to more linear swim pathway in the EA group compared with the VD model group (P < 0.01). The increasing expressions of p53 and Noxa play important roles in the pathogenesis of VD. EA improves learning and memory ability and protects pyramidal cells from apoptosis by blocking expression of p53 and Noxa in the hippocampal CA1 region of VD rats. These results suggest a novel mechanism of EA treatment to VD.

Chronic green tea catechins administration prevents oxidative stress-related brain aging in C57BL/6J mice

As the organism ages, production of reactive oxygen species (ROS) increases while antioxidants defense capability declines, leading to oxidative stress in critical cellular components, which further enhances ROS production. In the brain, this vicious cycle is more severe as brain is particularly vulnerable to oxidative damage. In our study, 14-month-old female C57BL/6J mice were orally administered 0.05% green tea catechins (GTC, w/v) in drinking water for 6 months. We found that GTC supplementation prevented the decrease in total superoxide dismutase and glutathione peroxidase activities in serum as well as reduced the thiobarbituric acid reactive substances and protein carbonyl contents in the hippocampus of aged mice. The activation of transcriptional factor nuclear factor-kappa B and lipofuscin formation in pyramidal cells of hippocampal CA1 region, which are all related to oxidative stress, was also reduced after GTC treatment. We also found that long-term GTC treatment prevented age-related reductions of two representative post-synaptic proteins post-synaptic density 95 and N-methyl- d-aspartate receptor 1 in the hippocampus. These results demonstrated that chronic 0.05% green tea catechins administration may prevent oxidative stress related brain aging in female C57BL/6J mice.

Cerebralcare Granule ®, a Chinese herb compound preparation, improves cerebral microcirculatory disorder and hippocampal CA1 neuron injury in gerbils after ischemia–reperfusion

Aim of the study Cerebralcare Granule ® (CG) is a Chinese herb compound preparation that has been used for treatment of cerebrovascular related diseases. However, the effect of post-treatment with CG on ischemia and reperfusion (I/R) induced cerebral injury is so far unclear. Materials and methods In present study, cerebral global I/R was induced in Mongolian gerbils by clamping bilateral carotid arteries for 30 min followed by reperfusion for 5 days, and CG (0.4 g/kg or 0.8 g/kg) was administrated 3 h after the initiation of reperfusion. Results Post-treatment with CG for 5 days attenuated the I/R-induced production of hydrogen peroxide in, leukocyte adhesion to, and albumin leakage from cerebral microvessels, and, meanwhile, protected neuron from death, reduced the number of caspase-3- and Bax-positive cells, and increased Bcl-2-positive cells in hippocampal CA1 region. Conclusion The results suggest that CG given after initiation of reperfusion is able to ameliorate cerebral microvascular dysfunction and hippocampal CA1 neuron damage caused by I/R.

Neuroprotective role of Batroxobin in cardiopulmonary resuscitation rabbits*

Background Batroxobin has been found to have protective effect on cerebral ischemia-reperfusion, and cardiopulmonary resuscitation (CPR) is the common cause of global brain ischemia-reperfusion. Objective To observe the effect of Batroxobin on the morphological results of cerebral cortex and hippocampus in rabbit models of CPR, and the changes of serum concentration of tumor necrosis factor alpha (TNF-a) after CPR. Design A randomized controlled observation. Setting Laboratory of the Department of Burns, Changhai Hospital affiliated to the Second Military Medical University of Chinese PLA. Materials Thirty healthy New Zealand rabbits of 2.5-3.0 kg, either male or female, were used. Kits for TNF-a determination were provided by LIFEKEY BioMeditech Company (USA). Methods The experiments were carried out in the laboratory of Department of Burns, Changhai Hospital from February 2001 to January 2002. The 32 rabbits were randomly divided into sham-operated group ( n=8), conventional resuscitation group ( n=12) and Batroxobin-treated group ( n=12). The animals in the conventional resuscitation group and Batroxobin-treated group were anesthetized, then induced into modified Pittsburg's model of mechanical ventricular fibrillation. Sham-operated group was discharged on the chest wall, which did not cause ventricular fibrillation. Conventional resuscitation group and Batroxobin-treated group were exposed to 6 minutes of cardiac arrest induced by ventricular fibrillation, then the resuscitation began. A dosage of 0.3 Bu/kg of Batroxobin was administered to the rabbits in the Batroxobin-treated group at the beginning of resuscitation. Blood sample was collected at 4 and 12 hours after CPR to determine the concentration of TNF-a in serum. After the second blood collection, brain tissue was taken out immediately, and the forms of nerve cells in cerebral cortex and hippocampal CA1 region were observed under light microscope. Main outcome measures ▪ TNF-aconcentration in serum at 4 and 12 hours after CPR; ▪ Forms of nerve cells in cerebral cortex and hippocampal CA1 region at 12 hours after CPR. Results All the 31 New Zealand rabbits were involved in the analysis of results. ▪ TNF-a concentration in serum: At 4 hours after CPR, the TNF-a concentrations in serum in the conventional resuscitation group and Batroxobin-treated group [(5.947±2.366), (5.122±2.521) ng/L] were significantly higher than that in the sham-operated group [(2.604±1.623) ng/L, P < 0.05]. At 12 hours after CPR, the TNF-a concentration in serum in the conventional resuscitation group was (7.770±3.121) ng/L, it was significantly higher than that at 4 hours ( P < 0.05), also significantly higher than that in the Batroxobin-treated group [(5.425±2.280) ng/L, P < 0.05]. ▪ Forms of nerve cells: In the sham-operated group, no abnormality was found in the hippocampal CA1 region and cerebral cortex. In the conventional resuscitation group, the pyramidal cells in hippocampal CA1 region were lined up in disorders, and edema, puff, vacuolization, nucleus concentration and anachromasis were also observed appeared; Edema of nerve cells, vacuole, pyknosis appeared in cerebral cortex; microthrombosis appeared in some blood capillaries. As compared with the conventional resuscitation group, cellular edema was relieved and pyknosis of nerve cells were obviously reduced, and no microthrombosis was found in hippocampal CA1 region and cerebral cortex in the Batroxobin-treated group. Conclusion Batroxobin have neuroprotective effect on CPR rabbits, and may inhibit the excessive increase of TNF-a concentration in serum.

Post-ischemic continuous administration of galantamine attenuates cognitive deficits and hippocampal neurons loss after transient global ischemia in gerbils

The deficits due to global cerebral ischemia show a close correlation with hippocampal CA1 neurons damage. Here we presented that galantamine showed effective protection against ischemic insults. In a transient brain global ischemic model conducted in gerbils, we investigated the alterations of performance in passive avoidance test and the histological changes between sham-operated animals (as controls) and those received post-ischemic continuous administration of saline (vehicle) or galantamine. Compared to the controls, gerbils received ischemic insults with saline treatment showed significant impairment in performance in passive avoidance test and dramatic loss of cells in hippocampal CA1 region. However, gerbils that received the same insults with galantamine (2 mg/kg/day) treatment performed similarly to the controls. Consistently, most of the cells in hippocampal CA1 region which were vulnerable to ischemic insults, survived after galantamine treatment. Our results suggested that continuous application of galantamine might be effective in treatment of ischemic injury.