[The role of somatostatin in area CA1 of rat hippocampus in experimental epilepy].

In area CA1, intrahippocampal microinjection of somatostatin(SS, 0.03 to 0.3 nmol) caused single or a series of spike-sharp waves in the cortex electroencephalogram (EEG), the spectrum average total power of which is increased dose-dependently from 0.006 to 0.15 nmol. Microinjection of SS into the hippocampal CA1 subregion brought out epileptic-like behavioral responses and aggregated kainic acid (KA)-induced epileptiform activity of rats. With extracellular recording technique, the effects of SS on 114 units epileptiform discharge were investigated in penicillin (PEN)-treated 95 rat hippocampal slices. In response to the application of SS (10(-10), 10(-8), 10(-6) mol/L), the burst frequency of area CA1 62/105 (59.05%) recorded unit discharges was increased significantly, while that of 23/105 (21.9%) was decreased. These results suggest that SS in hippocampal CA1 subregion mainly precipitates epileptiform discharge. The addition of anti-somatostatin antibody (1 1000) to the perfusate partly blocked the epileptiform bursts triggered by PEN perfusion, while this antiepileptic effect of SSAB was reversed by application of SS (10(-8) mol/L). These indicate that endogenous SS may be involved in epileptiform discharge in area CA1 of hippocampus.