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Objective:To evaluate the relationship between choline acetyltransferase (ChAT) positive neurons in parabrachial nucleus and development of fear memory in mice.Methods:Eighteen healthy male ChAT-ires-cre mice, aged 8-9 weeks, weighing 22-25 g, were divided into 3 groups ( n=6 each) using a random number table method: Cre-dependent AAV-DIO-hM 3Dq-mcherry (Gq) virus/clozapine-N-oxide (CNO) group (group Gq/CNO), Gq/normal saline (NS) group (group Gq/NS) and Cre-dependent AAV-DIO-mcherry (mc) virus/CNO group (group mc/CNO). Gq virus was injected into parabrachial nucleus, and CNO 2 mg/kg was injected intraperitoneally 3 weeks later in group Gq/CNO.Gq virus was injected into parabrachial nucleus, and the equal volume of normal saline was injected intraperitoneally 3 weeks later in group Gq/NS.In group mc/CNO, mc virus was injected into parabrachial nucleus, and CNO 2 mg/kg was injected intraperitoneally 3 weeks later.The fear conditioning test was performed at 30 min after intraperitoneal injection in all the 3 groups.The brains were then removed and sliced.The virus expression and areas of the brain projected by ChAT positive neurons were observed. Results:Compared with group Gq/CNO, the percentage of freezing time was significantly increased during testing phase in Gq/NS and mc/CNO groups ( P<0.05). Gq/mc virus carrying fluorescent protein mcherry was expressed in parabrachial nucleus and was co-expressed with mcherry-ChAT.The fibers of ChAT positive neurons projected to the red nucleus, substantia nigra, central amygdala, anterodorsal thalamic nucleus and bed nucleus of stria terminalis. Conclusion:The ChAT positive neurons in parabrachial nucleus are involved in the regulation of the development of fear memory in mice, which can impair fear memory, and the regulation is carried out probably through central amygdala.
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Objective To evaluate the changes in the expression of hippocampal α7 nicotinic ace-tylcholine receptor (α7nAChR) , acetylcholinesterase ( AChE) and choline acetyltransferase ( ChAT) after sevoflurane anesthesia in neonatal rats. Methods Seventy-two healthy Sprague-Dawley rats of both sexes, aged 7 days, weighing 25-40 g, were divided into 3 groups ( n=24 each) using a random number table method: control group ( group C) , air and oxygen group ( group A∕O) and sevoflurane group ( group S) . Rats were exposed to carrier gas ( air 1 L∕min plus oxygen 1 L∕min) for 2 h in group A∕O. Rats were ex-posed to 3. 4％ sevoflurane in carrier gas for 2 h in group S. Eight rats in each group were selected at 2 h, 1 week and 4 weeks after the end of inhalation, and sacrificed, brains were removed and hippocampal tis-sues were obtained for determination of α7nAChR, AChE and ChAT protein and mRNA by Western blot and real-time polymerase chain reaction, respectively. Results Compared with group A∕O, the expression of α7nAChR mRNA was significantly down-regulated at each time point after the end of inhalation, and the expression of TnAChR was down-regulated at 2 h after the end of inhalation and up-regulated at 1 week after the end of inhalation, the expression of AChE mRNA was up-regulated at 2 h after the end of inhalation and down-regulated at 4 weeks after the end of inhalation, the expression of AChE was down-regulated at 4 weeks after the end of inhalation, the expression of ChAT mRNA was up-regulated at 2 h after the end of in-halation, and the expression of ChAT was down-regulated at each time point after the end of inhalation in group S ( P<0. 05) . Conclusion The expression of hippocampal α7nAChR is down-regulated at first and then up-regulated after sevoflurane anesthesia, the expression of ChAT and AchE in the later period is down-regulated, the tendency of protein expression mentioned above is different from that of its mRNA ex-pression, suggesting that sevoflurane may affect the protein expression through other pathways.
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Objective To investigate the effects of postoperative sleep deprivation on the expression of choline acetyltransferase (ChAT) in hippocampi of aged rats.Methods Forty-eight male Wistar rats,aged 20 months,weighing 500-600 g,were randomly divided into 4 groups (n =12 each) using a random number table:control group (group C) ; operation group (group O) ; sleep deprivation group (group S) ; postoperative sleep deprivation group (group OS).Sleep deprivation was induced in the rats by housing them on small platforms over water.They fell into the water if they lost muscle tone.All the rats had free access to food and water.In group OS,splenectomy was performed,and all the rats underwent 24 h sleep deprivation after the rats were awake.All the rats underwent 24 h sleep deprivation at the corresponding time point in group S.Morris water maze test was carried out at 24 h after operation.The number of ChAT positive cells in the hippocampal CA1 region was counted after completion of Morris water maze test.Results Compared with group C,the escape latency was significantly prolonged,the time of staying at the original platform quadrant was shortened,and the frequency of crossing the original platform and the number of ChAT positive cells in the hippocampal CA1 region were decreased after operation in O and OS groups,and no significant changes were found in the parameters mentioned above in group S.Compared with group O,the escape latency was significantly prolonged,the time of staying at the original platform quadrant was shortened,the frequency of crossing the original platform was decreased,and there was no significant difference in the numberof ChAT positive cells in the hippocampal CA1 region in group OS,and no significant changes were found in the parameters mentioned above in group S.Compared with group S,the escape latency was significantly prolonged,the time of staying at the original platform quadrant was shortened,and the frequency of crossing the original platform and the number of ChAT positive cells in the hippocampal CA1 region were decreased after operation in group OS.Conclusion The mechanism by which postoperative sleep deprivation induces cognitive decline is not related to the expression of ChAT in hippocampi of aged rats.
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Objective To investigate the effects of radiofrequency thermocoagulation (RFT) on pathological features and the expressions of choline acetyltransferase (ChAT), vasoactive intestinal peptide (VIP) and nitric oxide synthase (NOS) at lower esophageal sphincter (LES) in family dogs. Methods A total of 15 dogs were randomly divided into three groups. Sham group underwent gastroscopy and was fed for 3 months (n=5). Dogs were given RFT and were fed for 24 h after RFT (n=5, RFT+24 h group). Dogs were given RFT and were fed for 3 months after RFT (n=5, RFT+3m group). The pathological changes of LES were observed after HE staining in three groups. The expressions of ChAT, VIP and NOS were detected by immunohistochemical method in three groups. Results Results of HE staining showed nearly the same tissues in Sham group and control group. There were active inflammatory reaction and structural damage in RFT+24 h group. The chronic in-flammatory reaction and structural remodeling were found in RFT+3m group. Immunohistochemistry showed that ChAT was significantly increased in RFT+3m group compare than that of Sham group. Values of VIP and NOS were significantly de-creased in RFT+3m group compare than that of Sham group (P<0.01). Conclusion The thickness and increased pressure of LES were found after RFT,which also caused changes in neurotransmitters of local tissues in dogs.
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ObjectiveTo investigate the effects of partial hepatic ischemia/reperfusion (I/R) on choline acetyltransferase(ChAT) expression in hippocampal neuron in mice.MethodsOne hundred adult male mice,aged 2 months,weighing 20-25 g,were randomly divided into 5 groups (n =20 each): normal control group(group C),sham operation group(group S),groups I/R1,I/R2,I/R3.Partial hepatic ischemia was produced by clamping left hepatic artery and portal vein for 20,30,40 min respectively followed by reperfusion in groups I/R1,I/R2,I/R3.Passive avoidance task was performed with 10 mice in each group at 4-9 and 18-23 d after operation respectively.The animals were sacrificed and their brains were removed for determination of the expression of ChAT in CA3 of hippocampal neuron.ResultsCompared with group C,the latency was significantly shortened and number of errors increased in groups I/R1 and I/R2 at 4-7 d after operation and in group I/R3 at 4-9 d after operation,the expression of ChAT in hippocampal neuron down-regulated in groups I/R1,I/R2 and I/R3 at 9 d after operation( P ＜0.05 or 0.01).There was no significant difference in the latency and number of errors at 18-23 d after operation and the expression of ChAT in hippocampal neuron at 23 d after operation among groups C,I/R1,I/R2 and I/R3 ( P ＞ 0.05).Compared with group I/R1,the number of errors was significantly increased at 4 and 5 d after operation in group I/R2,the latency shortened at 4-6 d after operation and number of errors increased at 4-9 d after operation in group I/R3,and the expression of ChAT in hippocampal neuron down-regulated at 9 d after operation in groups I/R2 and I/R3 ( P ＜ 0.05 or 0.01 ).There was no significant difference in the latency and number of errors at 18-23 d after operation and the expresson of ChAT in hippocampal neuron at 23 d after operation among groups I/R1,I/R2 and I/R3 ( P ＞ 0.05).ConclusionPartial hepatic I/R can result in transient cognitive impairment in mice by down-regulating the expression of ChAT in hippocampal neuron.
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Objective To investigate the effects of melatonin on choline acetyltransferase (ChAT) in rat hippocampus after isoflurane anesthesia. Methods Sixty male SD rats weighing 390 - 440 g were randomized into 5 groups (n = 12 each): control group (group C), 1% isoflurane group (group Ⅰ), 1% isoflurane + melatonin group (group IM) , 2% isoflurane group (group J) and 2% isoflurane + melatonin group (group JM) . In IM and JM groups, melatonin 10 mg/kg was administered intraperitoneally once a day for 7 consecutive days, while equal volume of normal saline was given intraperitoneally instead of melatonin in C, I and J groups. Groups Ⅰ and IM inhaled 1% isoflurane and groups J and JM 2% isoflurane for 4 h on 7th day. All the rats underwent Morris water maze test on the day after anesthesia for assessment of learning and memory ability (escape latency and probe time) . The training test was performed 4 times a day for S days. Six rats randomly selected from each group were sacrificed the end of the test. The blood samples were collected for detection of plasma melatonin level by ELISA.The brain tissues were removed for determination of the expression and activity of ChAT in hippocampus by Western blot or colorimetric assay. The left rats were selected and sacrificed for determination of the number of ChAT positive neurons in hippocampal CA1 region and entate gyrus by immunofluorescence. Results The plasma melatonin level and expression and activity of ChAT were significantly lower in group I than in group C ( P ＜ 0.01) . The escape latency was significantly longer, the probe time was significantly shorter, and the plasma melatonin level and expression and activity of ChAT were significantly lower in group J than in group C ( P ＜ 0.05 or 0.01) . The escape latency was significantly shorter, the probe time was significantly longer, and the plasma melatonin level and expression and activity of ChAT were significantly higher in group IM than in group Ⅰ ( P ＜ 0.05 or 0.01). The escape latency was significantly shorter and the plasma melatonin level and ChAT activity were significantly higher in group JM than in group J ( P ＜ 0.05 or 0.01) . The results of immunofluorescent staining showed that the number of ChAT positive neurons in hippocampal CA1 region and dentate gyrus wag consistent with the changes in the measured ChAT expression. Conclusion Melatonin can reduce isoflurane-mediated inhibition of ChAT expression and activity and thus improve spatial memory impaired by isoflurane anesthesia in rats.
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Objective To investigate the effects of almitrine-raubasine on learning-memory ability and brain choline acetyltransferase (ChAT) activity in chronic episodic hypoxia (EHYP) rat. Methods After establishing the rat model of EHYP, almitrine-raubasine (0.03 tablets/250 g body weight , Bid) was given to the EHYP rats. The learning-memory ability was evaluated by using passive avoidance test and the ChAT activity in three different brain regions (including cerebral cortex, hippocampus and striatum) was determined using radiochemical method. Results As compared with the controlled rats, the performance on passive avoidance test of EHYP rats was impaired significantly (P