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[Objective]To investigate the effects of the seed extract of Clausena lansium,N-methyl-N-cis-styryl-cinnamamide,on the penicillin-induced epilepsy in rats.[Methods]Thirty-two Sprague-Dawely rata were randomly divided into four groups with 8 rats in each group:normal control(20 mL/L Tween 80+Normal Saline),model control(20 mL/L Tween 80+Penicillin),low dose treatment(Cinnamamide 75 mg/kg+Penicillin),hish dose treatment(Cinnamamide 150 mg/kg+Penicillin).The epilepsy rat model was established by localized intracortical injections of penicillin.The effects of pretreatments of the rats with N-methyl-N-cis-styryl-cinnamamide(intraperitoneal injection,ip)on the penicillin-induced seizure activities and the epileptiform discharges recorded by electrocorticogram(ECoG)were observed.[Results]The penicillin-induced seizure was significantly lightened in both the pretreatment groups(75 and 150 mg/kg N-methyl-N-cis-styryl-cinnamamide),compared with the model group.N-methyl-N-cis-styryl-cinnamamide(75 and 150 mg/kg)could significantly prolonged the latency of epileptiform activities,shorten the duration of epileptiform discharges and decreased the mean spike frequency in the late stage(P＜0.05 or P＜0.01).However,there was no significant difference in the highest value or the lowest value of the epileptiform waves between the model and cinnamamide treatment groups.[Conclusion]The seed extract of Clansena lansium,N-methyl-N-cis-styryl-cinnamamide,can significantly inhibit the seizure and epileptiform discharges caused by penicillin-localized injections in the cortex of rats,suggesting that the natural substance has an anticonvulsive function.
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BACKGROUND: Body temperature has significant effects on brainstem auditory evoked potentials (BAEP). The wave latency of BAEP is the sensitive and objective index for reflecting the effects of body temperature on the synaptic transmission and nerve fiber conduction. The wave origin of electrocochleogram (ECochG) and the effects of body temperature on it need to be probed into to further define its wave origin so as to guide its clinical application.OBJECTIVE: To observe the effects of body temperature on ECochG and provide important basis for further defining its wave origin and guiding its clinical application.DESIGN: A randomized block design.MATERIALS: This study was performed in the Department of Physiology, Medical College of Jinan University between July and September 2002. Forty adult guinea pigs were randomly divided into hypothermia group (n=20) and hyperthermia group (n=20).INTERVENTIONS: The body temperature of the guinea pigs was decreased or increased step by step with their body contacted with physical method. and the changed rate of body temperature was kept as decreased or increased by 1 ℃ every 5-10 minutes. BAEP and ECochG were detected when the body temperature was changed by 1 ℃.MAIN OUTCOME MEASURES: The PL and IPL of BAEP and ECochG were observed.RESULTS: Finally, 37 guinea pigs were involved in the analysis of relonged as the body temperature was decreased step by step from 36 ℃ to 25 ℃, and shortened as the body temperature was increased gradually from 36 ℃ to 42 ℃. The PL and Ⅰ-Ⅳ IPL prolonged or shortened more significantly with the temperature changed. The PL of wave N1, N2 and N3 and N1-N3 IPL of ECochG also prolonged or shortened as the body temperature perature,the total prolonged and shortened values of Ⅰ -Ⅳ IPL representing the central transmission time of brainstem were much greater than that of wave Ⅰ PL representing the peripheral conduction time, .and the total prolonged and shortened values of thePL of wave Ⅱ , Ⅲ and Ⅳ originating from the brainstem centers were much greater than that of wave Ⅰ originating fromthe auditory nerve. The total prolonged and shortened values of N1-N3 IPL were greater than that of wave N1 PL representing the peripheral conduction time, and the total prolonged and shortened values of the PL of wave N2 and N3 were much greater than that of wave N1 originating from the auditorynerve.CONCLUSION: The significant effects of body temperature on ECochG are similar to those of BAEP, and the origin of wave N2 and N3 of ECochG is higher than that of wave N1 that originates from the auditory nerve.
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AIM: To investigate the role of brainstem auditory evoked potential(BAEP) in the early diagnosis of diabetic central neuropathy (DCN) and to probe into the relationship between plasma nitric oxide (NO) and DCN. METHODS: Experimental diabetes(ED) rat model was used. BAEP and plasma NO were measured dynamically after ED modeling. RESULTS: The peak latency (PL) of Ⅰ, Ⅲ, Ⅳ and V and the interpeak latency (IPL) of I-III and III-V of BAEP in ED group prolonged after 4 weeks of ED modeling (P＜0.05). All PL and IPL of BAEP prolonged after 6 weeks、8 weeks and 10 weeks (P＜0.01). The plasma NO increased to the top in ED group at 2 weeks and then decreased gradually. There was negative correlation between plasma NO and PL and IPL of BAEP. CONCLUSION: BAEP was sensitive and valuable in the early diagnosis of DCN. Reduction of plasma NO may play a role in the pathogenesis of DCN.
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The abnormality of the central noradrenergic system in Alzheimer's disease has two cases: decrease or increase. The former is easy to be understood, because it is resulted from the outstanding forfeit of the noradrenergic neurons in the nucleus locus ceruleus (nLC); but the noradrenalin concentration does not change and enen increase, it seems to disagree with the loss of the noradrenergic neurons in the nLC. This article put emphasis on it, enumerated the related evidence and analyzed the possible causes. At present time, the drugs to increase noradrenalin is used mostly in clinic. This paper summarized it and put forth our own opinions.
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AIM:To explore the roles of brain-stem auditory evoked potential(BAEP) in early monitoring the hearing loss and brain damages in hyperbilirubinemia and nitric oxide(NO) in the pathogenesis of bilirubin-induced hearing loss and brain damages.METHODS:Different doses of bilirubin solution(30 mg/kg,60 mg/kg,90 mg/kg,120 mg/kg and 150 mg/kg) were injected into the abdominal cavity of 15-day old SD rats to make the animal model of hyperbilirubinemia.The serum concentrations of bilirubin were detected by a micro-gauge.The bilirubin concentrations in the brain tissues were examined via a diazo method.The Na+-K+ATPase activities in the brain tissues were analyzed by rooting phosphorus.The NO contents in the brain tissues were assayed via the method of nitrate reductase.BAEP were recorded with an evoked potential recorder.RESULTS:After making the ejection,parts of the rats in the high dosage groups(120 mg/kg and 150 mg/kg) showed the abnormal neuro-behaviors.After 6 hours of the ejection,the bilirubin concentrations in serum and in brain tissues,and NO contents in the brain tissues were increased significantly.The Na+-K+ATPase activities in the brain tissues were decreased obviously,and the PL and IPL of BAEP were prolonged significantly in all the experimental rats except the ones in low dosage group(30 mg/kg).The changes of them were closely related to the dose of injected bilirubin.CONCLUSION:The PL and IPL of BAEP are the objective and sensitive indexes for early monitoring the hearing loss and brain damages in hyperbilirubinemia.NO may plays a certain role in the pathogenesis of bilirubin induced hearing loss and brain damages.
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AIM: To observe the relationship between noradrenaline and the synaptic configuration in rat hippocampus CA3 area. METHODS: Noradrenergic system injured models were produced by injecting 6-hydroxydopamine into rats' bilateral dorsal noradrenergic bundle. Then Y-type maze tests and elicitation of P3-like were carried out respectively before and after the model was established. The parameters of synaptic configuration in the hippocampus CA3 areas were also analyzed quantitatively. RESULTS: The decreases in the thickness of postsynaptic density material, the curvature of synaptic interface and the occurrence of perforated synapses, and the increase in the width of synaptic cleft were observed. CONCLUSION: The normal noradrenalin level in hippocampus is necessary to maintain the normal synaptic interface ultrastructure in hippocampus CA3 area.
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AIM: To investigate the role of brainstem auditory evoked potential(BAEP) in the early diagnosis of diabetic central neuropathy (DCN) and to probe into the relationship between plasma nitric oxide (NO) and DCN. METHODS: Experimental diabetes(ED) rat model was used. BAEP and plasma NO were measured dynamically after ED modeling. RESULTS: The peak latency (PL) of Ⅰ, Ⅲ, Ⅳ and V and the interpeak latency (IPL) of I-III and III-V of BAEP in ED group prolonged after 4 weeks of ED modeling (P