Baicalin Ameliorates Corticosterone-Induced Depression by Promoting Neurodevelopment of Hippocampal via mTOR/GSK3β Pathway / 中国结合医学杂志

OBJECTIVE@#To investigate the role of hippocampal neurodevelopment in the antidepressant effect of baicalin.@*METHODS@#Forty male Institute of Cancer Research mice were divided into control, corticosterone (CORT, 40 mg/kg), CORT+baicalin-L (25 mg/kg), CORT+baicalin-H (50 mg/kg), and CORT+fluoxetine (10 mg/kg) groups according to a random number table. An animal model of depression was established by chronic CORT exposure. Behavioral tests were used to assess the reliability of depression model and the antidepressant effect of baicalin. In addition, Nissl staining and immunofluorescence were used to evaluate the effect of baicalin on hippocampal neurodevelopment in mice. The protein and mRNA expression levels of neurodevelopment-related factors were detected by Western blot analysis and real-time polymerase chain reaction, respectively.@*RESULTS@#Baicalin significantly ameliorated the depressive-like behavior of mice resulting from CORT exposure and promoted the development of dentate gyrus in hippocampus, thereby reversing the depressive-like pathological changes in hippocampal neurons caused by CORT neurotoxicity. Moreover, baicalin significantly decreased the protein and mRNA expression levels of glycogen synthase kinase 3β (GSK3β), and upregulated the expression levels of cell cycle protein D1, p-mammalian target of rapamycin (mTOR), doublecortin, and brain-derived neurotrophic factor (all P<0.01). There were no significant differences between baicalin and fluoxetine groups (P>0.05).@*CONCLUSION@#Baicalin can promote the development of hippocampal neurons via mTOR/GSK3β signaling pathway, thus protect mice against CORT-induced neurotoxicity and play an antidepressant role.

Effects of Pilocarpine-induced Seizures on the Neuronal Cell Death, Mossy Fiber Sprouting and Neurogensis in the Hippocampus of Mice / 체질인류학회지

Present study was performed to delineate the inter-relationship among neuronal death, mossy fiber sprouting (MFS) and neurogenesis in hippocampal formation of pilocarpine-treated mice. Status epilepticus was induced by intraperitoneal administration of 300 mg/kg pilocarpine in male ICR and C57BL/6 mouse. The severity of seizure was evaluated using 5 grades of Racine scales for first 4 hr after pilocarpine injection. Fluro-Jade C (FJC) staing, NeoTimm's staining and immunohistochemistry for BrdU were employed to evaluate neuronal cell death, MFS and neurogenesis, respectively. All animals in the present study induced seizures over grade 3 of Racine scale by pilocarpine injection. ICR mice show higher seizure severity (mean Racine scale; 4.37) than C57BL/6 mice do (mean Racine scale; 3.22), while the latency times for the first seizure over Racine scale grade 3 are from 15 min to 20 min and showed no difference between the 2 strains. In ICR mouse, numerous FJC-positive cells in hilus of hippocampus were detected at 4 h after pilocarpine injection, while they were not detected at that time in C57BL/6 mouse. The number of FJC-positive neuronal cells, which were densely found in the pyramidal layer of CA1, CA3 and hilus polymorphic regions of hippocampus, reached peak at 3 days after injection and then few cells were found at 7 days after injection in both strains. In control animals, BrdU positive cells in dentate subgranular layer which represent the hippocampal neurogenesis were more numerous in C57BL/6 than in ICR. The number of BrdU positive cells significantly increased at 2 days after pilocarpine injection and reached the peak at 8 days after injection and returned to control level at 15 day after injection in both strains. The percent increase of the BrdU positive cell was more prominent in ICR mouse. MFS was found at 2 weeks after the injection and the intensity of MFS was getting strong at 4 weeks after injection. There was no differences in MFS grading between 2 strains. These results suggest that there are some inter-relationships among the seizure severity, hippocampal neuronal cell death and hippocampal neurogenesis, but they don't have any significant relationships with the mossy fiber sprouting from dentate granule cells.

Protective effect of Chinese Medical Formula Decoction on anoxic damage in cultured hippocampal neuronal cells from newborn rats / 中国康复理论与实践

@#ObjectiveTo study the protective effect of Chinese Medical Formula Decoction on anoxic damage in cultured hippocampal neuronal cells from newborn rats. MethodsThe sera with Chinese Medicine (SCM-1,2,3) were collected from rats fed on Chinese Medical Formula Decoction Ⅰ,Ⅱ,Ⅲ(CMFD-Ⅰ,Ⅱ,Ⅲ) for 3 days,while the sera of rats which were fed with normal saline was collected as control. Hippocampal neuronal cells were obtained from dissociated cerebrella of 2 day old Wister rats. The cells were maintained in 5% CO2 humidified atmosphere at 37℃. After 7 days, the cells were grown in culture media containing SCM-1,2,3 and normal saline for 24 hours and in anoxic atmosphere for 1 hour. After anoxia, the cells were cultured for 24 hours. Culture media were collected and Malonaldehyde (MDA) and Lactate Dehydrogenase (LDH) in culture media were detected. ResultsThe survival neuronal cell rate in SCM-1 and 2 groups were significantly higher than control group. LDH and MDA in culture media of SCM-1 and 2 groups were lowed than control group. Conclusions There is a protective effect of CMFD-1 and 2 on anoxic damage in cultured hippocampal neuronal cells from newborn rats.

Synaptic Localization of NMDA Receptor and Shank Protein in Hippocampal Neuron in Vitro / 대한해부학회지

The existence of NMDA receptor and a new organizer protein, Shank, in the postsynaptic density was studied with the cultured hippocampal neurons using by double immunofluorescence method. The hippocampi from embryonic 18 days were dissected and hippocampal neurons were obtained from dissociated hippocampi with 0.25% trypsin and 0.1% DNase in PBS. The hippocampal neurons were plated with density 3,600/cm2 on the poly-L-lysine coated coverglass and cultured 37degrees C, 5% CO2 incubator for 5 weeks. The N2 supplemented MEM was used as a culture medium. Following results are obtained from experiments: 1. The 3~5 minor processes from the cell body of hippocampal neurons were observed at 20 hr in vitro. One of the minor processes was elongated and looked like an axon, and another minor processes showed dendritic branching pattern with slender in thickness. 2. The excitatory NMDA receptor colocalized with PSD-95 which is the postsynaptic density protein. The presynaptic protein, synapsin 1, was closely apposed with PSD-95. 3. Shank which is an organizer protein colocalize with NMDA receptor/PSD-95 complex in the postsynaptic density. Shank proteins may be concerned with the cluster formation of NMDA receptor/PSD-95 in the postsynaptic membrane.