[Effects of Long-Term Ethanol Consumption on Learning-Memory Functions in Mice and the Mechanisms Involved].

Objective: To investigate the effect of long-term ethanol consumption on learning-memory functions in mice and the mechanisms involved. Methods: Thirty male C57BL6/J mice were randomly assigned to 3 groups, with 10 mice in each group. The three groups included a control group in which the mice were given water ad libitum for 30 days, a long-term ethanol consumption group, or the EtOH group, in which the mice were given 6% (volume fraction) ethanol ad libitum for 30 days, and a long-term alcoholism group, or the EtOH+G group, in which the mice were given 5% (volume fraction) ethanol ad libitum for 30 days plus intermittent intragastric gavage of 20% ethanol at 3.5 g per kilogram body mass once every three days. After 30 days, the learning-memory functions of the mice were evaluated. At the conclusion of the experiment, the brain tissue of the mice was collected in order to examine the oxygen consumption rate (OCR) of mitochondria, the levels of pan-acetylation and protein oxidative stress in the hippocampal tissue, and the expression of sirtuin-3 (SIRT3) in hippocampus. Results: Morris water maze test showed that, compared with those of the control group, the times of crossing the platform and the percentage of platform time in the EtOH group and the EtOH+G group were both lower, and the EtOH+G group had the lowest results ( P<0.05). Western blot results showed that long-term ethanol intake increased the levels of protein oxidative stress and pan-acetylation in the hippocampal tissue and down-regulated SIRT3 expression of hippocampal mitochondria. The results of mitochondrial complex Ⅱ respiration showed that the brain mitochondrial 3-state respiration in the EtOH group and the EtOH+G group was lower than that in the control group ( P<0.05). Compared that with the control group, the mitochondrial maximum respiration in EtOH+G group was decreased ( P<0.05). Conclusions: Both long-term ethanol consumption and long-term alcoholism can reduce learning-memory functions and long-term alcoholism has the greater impact of the two. The potential mechanism may involve the down-regulation of the expression of SIRT3 protein in the hippocampus, which results in an increased level of pan-acetylation and enhanced expression of oxidative stress protein in the hippocampus, affects the mitochondrial functions of the brain, inhibits the oxidative phosphorylation capacity of mitochondrial complex Ⅱ, reduces the ATP energy supply of the brain tissue, and thus affects the learning-memory function.

[Effects of electroacupuncture on learning-memory function and synaptic plasticity in rats with cerebral ischemia-reperfusion injury based on the BDNF/TrkB pathway].

OBJECTIVE: To observe the effects of electroacupuncture (EA) at "Baihui" (GV 20) and "Sishencong" (EX-HN 1) on the expression of brain-derived neurotrophic factor (BDNF)/tyrosine kinase receptor B (TrkB) pathway, synaptophysin (SYN), and the levels of interleukin-1ß (IL-1ß) and interleukin-18 (IL-18) in the hippocampus of the ischemic side in rats with cerebral ischemia-reperfusion injury (CIRI), and to explore the effects and action mechanism of EA on post-CIRI learning-memory function. METHODS: Forty-eight SPF-grade male SD rats were randomly divided into a sham operation group, a model group, an EA group, and a non-acupoint group, with 12 rats in each group. The CIRI model was established in the model group, the EA group, and the non-acupoint group using the modified ZeaLonga suture method. The rats in the EA group were treated with EA at "Sishencong" (EX-HN 1) and "Baihui" (GV 20), with disperse-dense wave at frequency of 2 Hz/10 Hz and intensity of 1 mA. The rats in the non-acupoint group were treated with EA at non-meridian and non-acupoint points under the ribs bilaterally with the same parameters as the EA group. EA were conducted for 30 min each session, once daily, for 7 days. During the intervention, body weight was measured daily at a fixed time, and neurological deficits were assessed on the 1st, 3rd, and 7th days into intervention. Brain infarct volume was measured using small animal magnetic resonance imaging before and after the intervention. After the intervention, learning-memory function were evaluated using the Morris water maze. Hippocampal morphology was observed with HE staining. The positive expression of SYN in the hippocampus of the ischemic side was detected by immunohistochemistry. BDNF, TrkB, and SYN protein expressions in the hippocampus of the ischemic side were detected by Western blot. IL-1ß and IL-18 levels in the hippocampus of the ischemic side were measured by ELISA. RESULTS: From the 2nd to the 7th day into intervention, compared with the sham operation group, the body weight of rats in the model group was decreased (P<0.01); compared with the model group and the non-acupoint group, the body weight of rats in the EA group was increased (P<0.01). On the 1st day into intervention, compared with the sham operation group, neurological function scores of rats in the model group, the EA group, and the non-acupoint group were increased (P<0.01); on the 3rd and 7th days into intervention, neurological function scores of rats in the model group were higher than those in the sham operation group (P<0.01); on the 7th day, neurological function scores of rats in the EA group were lower than those in the model group and the non-acupoint group (P<0.05). Compared with the sham operation group, escape latency was prolonged (P<0.05), and the number of platform crossings was decreased (P<0.01) in the model group; compared with the model group and the non-acupoint group, escape latency was shortened (P<0.05), and the number of platform crossings was increased (P<0.01) in the EA group. Before intervention, the high signal infarcts were observed in the left ventricles of rats in the model group, the EA group, and the non-acupoint group; after intervention compared with the model group and the non-acupoint group, infarct volume in the EA group was decreased (P<0.01). Neuronal cells in the model group and the non-acupoint group were sparsely and disorderedly arranged, with deep-stained cytoplasm and shrunken nuclei; the number and arrangement of neuronal cells in the EA group were similar to the sham operation group, with less deep-stained cytoplasm and shrunken nuclei compared to the model group. Compared with the sham operation group, the positive expression of SYN, and BDNF TrkB, and SYN protein expressions in the hippocampus of the ischemic side were decreased (P<0.01, P<0.05), while levels of IL-1ß and IL-18 were increased (P<0.01) in the model group; compared with the model group and the non-acupoint group, the positive expression of SYN, and BDNF, TrkB and SYN protein expressions in the hippocampus of the ischemic side were increased (P<0.01, P<0.05), while levels of IL-1ß and IL-18 were decreased (P<0.01) in the EA group. CONCLUSION: EA at "Baihui" (GV 20) and "Sishencong" (EX-HN 1) may improve learning-memory function in rats with CIRI by activating the BDNF/TrkB signaling pathway, reducing neuroinflammatory response, and promoting the recovery of synaptic plasticity.

Effect of Suanzaoren Tang on Learning-memory Function and NLRP3 Pathway in Sleep-deprived Rats / 中国实验方剂学杂志

Objective:To explore the mechanism of Suanzaoren Tang in improving learning-memory of sleep-deprived rats based on Nod-like receptor 3 （NLRP3） inflammatome pathway. Method:The rats were randomly divided into normal control group， model group， Eszolam group（5.4×10^-4 g·kg^-1·d^-1）， low-dose Suanzaoren Tang group（4.59 g·kg^-1·d^-1）and high-dose Suanzaoren Tang group （18.36 g·kg^-1·d^-1）. In addition to normal control group， other groups were used to constructed sleep-deprived model， which was concurrent with 30-day continuous drug administration. Water maze was used to evaluate the learning-memory function of rats； The mRNA and protein expressions of NLRP3， apoptosis-related speckle proteins （ASC）， aspartic acid-specific cysteine protease-1 （Caspase-1）， interleukin-1（IL-1） and IL-18 in the hippocampus of rats were detected by Real-time fluorescence quantitative polymerase chain reaction （Real-time PCR） and Western blot. Result:Compared with control group， the incubation period of the platform， the total distance of swimming and the duration of first reaching the platform in model group were significantly increased （<italic>P</italic><0.01）， while the number of platform crossings and the target quadrant time were decreased （<italic>P</italic><0.01）. Compared with the model group， the incubation period， total swimming distance and the duration of first reaching the platform in low-dose Suanzaoren Tang group and high-dose Suanzaoren Tang group were decreased to different degrees （<italic>P</italic><0.05，<italic>P</italic><0.01）， while the number of platform crossings and the target quadrant time were increased significantly （<italic>P</italic><0.05，<italic>P</italic><0.01），but with no significant change in estazolam group. Compared with normal control group， mRNA and protein expressions of NLRP3， ASC， Caspase-1， IL-1<italic>β</italic>， IL-18 in the hippocampus of the model group were significantly increased （<italic>P</italic><0.05，<italic>P</italic><0.01）. Compared with model group， mRNA and protein expressions of NLRP3， ASC， Caspase-1， IL-1<italic>β</italic> and IL-18 in the hippocampus of the rats in low-dose Suanzaoren Tang group and high-dose Suanzaoren Tang group were all decreased to different degrees （<italic>P</italic><0.05）. The mRNA and protein expressions of NLRP3， ASC， Caspase-1， IL-1<italic>β</italic> and IL-18 in the hippocampus of Suanzaoren group also decreased， but with no significant change. Conclusion:Suanzaoren Tang can improve the learning-memory function of sleep-deprived rats， and its mechanism is related to the inhibition of NLRP3 inflammatome pathway in hippocampus and the alleviation of neuroinflammation.

Effects of Extractive from Gastrodiae Rhizoma on Learning-Memory Function in Mice / 中国中医药信息杂志

Objective To evaluate the effects of extractive from Gastrodiae Rhizoma on acquisition, consolidation and retrieval of learning-memory function in mice;To provide some reference for clinical research and development of new drugs.Methods Male Kunming mice were randomly divided into control group, model group, positive control group and Gastrodia extractive group. Positive control group and Gastrodia extractive group were given gavage by using relevant medicine 0.2 mL/10 g, and the control group and model group were given gavage with the same amount of distilled water for 16 days. After receiving gavage for continuous 11 days, memory acquisition barrier model was induced by scopolamine;memory consolidation barrier model was induced by chloromycetin;memory retrieval barrier model was induced by EtOH. The learning-memory function was reviewed by escape latency and spatial search distance. The quadrant and distance search time percentage was detected through directional navigation test and spatial probe test in Morris water maze.Results Extractive from Gastrodia Rhizoma shortened the time for acquisition, consolidation and retrieval of learning memory about escape latency and spatial search distance (P<0.05,P<0.01), and the quadrant and distance search time percentage were prolonged (P<0.01).Conclusion Extractive from Gastrodia Rhizoa can effectively improve the acquisition, consolidation and retrieval of learning-memory function in mice.