Long-term potentiation and the effects of 3 convulsants on its induction in hippocampal slices of rats / 第三军医大学学报

ABSTRACT

Long-term potentiation (LTP) of synaptic transmission between the dendrites of the pyramidal cells of CA[ region and the Schaffer-commissu-ral pathway was induced with electric stimulation in the isolated hippocampal slices of rats.The effects of 3 convulsants,soman,kianic acid.and picroto-xin,on the induction of LTP in this region were observed.It was found that a short series of electric impulses could effectively induce LTP in most of the slices of the hippocampus and the amplitude of the population spikes showed a similar change as the field excitatory postsynaptic potential did in the rising phase.Picrotoxin could facilitate the induction of LTP when it evoked an epileptoform electric activity in the slices,kianic acid could also evoke an epileptoform activity but significantly blocked the induction of LTP,and soman could not evoke obvious epileptoform activity but blocked the induction of LTP.The above findings suggest that a short series of electric impulses can effectively induce LTP between the pyramidal cells and the Schaffer-commisural pathway in the CA1 region,the effects of epileptoform activity on the induction of LTP depends on the mechanism to evoke the epileptoform activity,and the effects of soman on the induction of field potential may involve the noncholi-nergic system in the synaptic connections.