Effect of Suanzaoren Decoction on expression of ionotropic glutamate receptors and synaptic plasticity in hippocampus of anxiety rats / 中国中药杂志

This study investigated the effect of Suanzaoren Decoction on the expression of N-methyl-D-aspartate receptors(NMDAR) and α-amino-3-hydroxy-5-methyl-4-isoxazole-propionic acid receptors(AMPAR) in the hippocampus and synaptic plasticity in rats with conditioned fear-induced anxiety. The effect of Suanzaoren Decoction on rat behaviors were evaluated through open field experiment, elevated plus maze experiment, and light/dark box experiment. Enzyme-linked immunosorbent assay(ELISA) was used to measure the levels of glutamate(Glu) and γ-aminobutyric acid(GABA) in the rat hippocampus. Real-time fluorescence quantitative PCR(qRT-PCR) and Western blot were employed to assess the gene and protein expression of ionotropic glutamate receptors in the hippocampal region. Transmission electron microscopy was utilized to observe the changes in the ultrastructure of synaptic neurons in the hippocampal region. Long-term potentiation(LTP) detection technique was employed to record the changes in population spike(PS) amplitude in the hippocampal region of mice in each group. The behavioral results showed that compared with the model group, the Suanzaoren Decoction group effectively increased the number of entries into open arms, time spent in open arms, percentage of time spent in open arms out of total movement time, number of entries into open arms out of total entries into both arms(P<0.01), and significantly increased the time spent in the light box and the number of shuttle crossings(P<0.01). There was an increasing trend in the number of grid crossings, entries into the center grid, and time spent in the center grid, indicating a significant anxiolytic effect. ELISA results showed that compared with the model group, the Suanzaoren Decoction group exhibited significantly reduced levels of Glu, Glu/GABA ratio(P<0.01), and significantly increased levels of GABA(P<0.01) in the rat hippocampus. Furthermore, Suanzaoren Decoction significantly decreased the gene and protein expression of NMDAR(GluN2B and GluN2A) and AMPAR(GluA1 and GluA2) compared with the model group. Transmission electron microscopy results demonstrated improvements in synapses, neuronal cells, and organelles in the hippocampal region of the Suanzaoren Decoction group compared with the model group. LTP detection results showed a significant increase in the PS amplitude changes in the hippocampal region of Suanzaoren Decoction group from 5 to 35 min compared with the model group(P<0.05, P<0.01). In conclusion, Suanzaoren Decoction exhibits significant anxiolytic effects, which may be attributed to the reduction in NMDAR and AMPAR expression levels and the improvement of synaptic plasticity.

Role of hippocampus NMDAR subunits in electroacupuncture at "Zhongwan" (CV 12) and "Weishu" (BL 21) for gastric motility / 中国针灸

OBJECTIVE@#To observe the effects of electroacupuncture (EA) on gastric motility, protooncogene c-fos and hippocampus N-methyl-D-aspartate (NMDA) receptor subunits in rats with functional dyspepsia (FD), and to discuss the molecular mechanism of hippocampal in EA at "Zhongwan" (CV 12) and "Weishu" (BL 21) for gastric motility.@*METHODS@#Eighty-four Sprague Dawley (SD) rats were randomly divided into a normal group, a model group, a Zhongwan group, a Weishu group, an acupoint combination group and a non-acupoint group, 14 rats in each one. Except for the normal group, FD model were established by moderate tail-clipping infuriation method and irregular feeding. The rats in the Zhongwan group, Weishu group, acupoint combination group and non-acupoint group were treated with EA at corresponding acupoints, 20 min per treatment, once a day for 7 days. The rats in the normal group and the model group received no treatment; grabbing and fixation were applied in the model group. The stress transducer was used to record gastric motion waveforms; immunohistochemistry method was used to detect the expression of c-fos in hippocampus; Western blot method was used to detect the expression of NMDA receptor subunits NR1, NR2A and NR2B in hippocampus.@*RESULTS@#Compared with the normal group, the gastric motility range was decreased (0.05). Compared with the model group, the gastric motility range was increased, the expression of hippocampus c-fos and expression of hippocampus NR2A was increased but expressions of NR1 and NR2B were reduced in the Weishu group, Zhongwan group and acupoint combination group (0.05). Compared with the Zhongwan group and the Weishu group, the gastric motility range was increased, the expression of hippocampus c-fos and NR2A was increased but the expression of NR1 and NR2B was reducedin the acupoint combination group (0.05).@*CONCLUSION@#EA at "Zhongwan" (CV 12) and "Weishu" (BL 21) could increase gastric motility of FD rats, which is likely to be related with activating hippocampal neurons, upregulating the level of NR2A and downregulating NR1 and NR2B.

EXPRESSION OF MAPK AND NMDAR IN THE HIPPOCAMPUS OF ALZHEIMER RAT / 解剖学报

Objective To investigate the changes of expression of N-methyl-D-aspartate receptor(NMDAR)and mitogen activated protein kinase(MAPK)in Alzheimer disease(AD)rat model. Methods AD rat model was established by injection of amyloid-beta protein 1-40 1?l(10 g/L)into hippocampus of rat.NMDAR-mRNA and MAPK protein were immunostained by in situ hybradization histochemistry and immunohistochemistry respectively.Learning and memory ability,LTP were determined by Morris water maze and electrophysiological methods respectively. Results The escape latent was prolongated in Alzheimer rats two weeks after injection of A? than in control rats and in rats before the injection of A?(P