Objective: To investigate temporospatial changes of mG1uR1 mRNA expression in rat hippocampus during seizures induced by kainic acid. Methods: Using in situ hybridization with Dig-labeled cDNA probes to examine mG1uR1...Objective: To investigate temporospatial changes of mG1uR1 mRNA expression in rat hippocampus during seizures induced by kainic acid. Methods: Using in situ hybridization with Dig-labeled cDNA probes to examine mG1uR1 mRNA expression. The relative number of hybridization signal was quantified by image analysis systems. EEG and behavior changes of the rats were simultaneously observed. Results: All rats of the KA-injected group exhibited severe limbic convulsions. The EEG recordings also showed electrical seizure activities. The mG1uR1 mRNA expression began to increase at 1 h after KA injection and reached its maximal level at 4 - 8 h, and then it began to decrease gradually and came to the lowest by the end of 72 h. Conclusion: The enhanced early expression of mG1uR1 mRNA in hippocampus suggested that mG1uR1 may play an important role in epilepogenesis and may be related to the subsequent neuronal damage.展开更多
Hippocampal EEG and unit activities were recorded after seizures were initiated withintracerebroventricular injection of kainic acid (KA) in rats. Three kinds of hippocampal unit re-sponses to KA were found:1. Positiv...Hippocampal EEG and unit activities were recorded after seizures were initiated withintracerebroventricular injection of kainic acid (KA) in rats. Three kinds of hippocampal unit re-sponses to KA were found:1. Positive units: These units were characterized by high frequency burst firing temporally coincidentwith each hippocampal EEG spike.2. Negative units: These units showed a cessation of firing during each EEG paroxysm.3. Indifferent units: These units showed no evident chanses coincident with EEG paroxysms.Most positive units were hippocampal complex spike cells which correspond histologically tohippocampal pyramidal cells, and most complex spike cells fired in positive bursts after KA treat-ment. In the early period after KA injection, the positive units were concentrated in CA3 area. It was suggested that the activities of positive units may be considered as the typical epileptiformhippocampal unit activity induced by KA, and the firing features of negative units ma be the resultof the influence of hippocampal inhibitory interneurons or the result of excessive cellulardepolarization, and that hippocampal pyramidal cells were more sensitive to the epileptogenic ef-fect of KA than hippocampal intemeurons, and some pyramidal cells in CA3, in particular,may serve as "epileptic pacemaker neurons " in KA-induced epileptogenesis.展开更多
文摘Objective: To investigate temporospatial changes of mG1uR1 mRNA expression in rat hippocampus during seizures induced by kainic acid. Methods: Using in situ hybridization with Dig-labeled cDNA probes to examine mG1uR1 mRNA expression. The relative number of hybridization signal was quantified by image analysis systems. EEG and behavior changes of the rats were simultaneously observed. Results: All rats of the KA-injected group exhibited severe limbic convulsions. The EEG recordings also showed electrical seizure activities. The mG1uR1 mRNA expression began to increase at 1 h after KA injection and reached its maximal level at 4 - 8 h, and then it began to decrease gradually and came to the lowest by the end of 72 h. Conclusion: The enhanced early expression of mG1uR1 mRNA in hippocampus suggested that mG1uR1 may play an important role in epilepogenesis and may be related to the subsequent neuronal damage.
文摘Hippocampal EEG and unit activities were recorded after seizures were initiated withintracerebroventricular injection of kainic acid (KA) in rats. Three kinds of hippocampal unit re-sponses to KA were found:1. Positive units: These units were characterized by high frequency burst firing temporally coincidentwith each hippocampal EEG spike.2. Negative units: These units showed a cessation of firing during each EEG paroxysm.3. Indifferent units: These units showed no evident chanses coincident with EEG paroxysms.Most positive units were hippocampal complex spike cells which correspond histologically tohippocampal pyramidal cells, and most complex spike cells fired in positive bursts after KA treat-ment. In the early period after KA injection, the positive units were concentrated in CA3 area. It was suggested that the activities of positive units may be considered as the typical epileptiformhippocampal unit activity induced by KA, and the firing features of negative units ma be the resultof the influence of hippocampal inhibitory interneurons or the result of excessive cellulardepolarization, and that hippocampal pyramidal cells were more sensitive to the epileptogenic ef-fect of KA than hippocampal intemeurons, and some pyramidal cells in CA3, in particular,may serve as "epileptic pacemaker neurons " in KA-induced epileptogenesis.
