抄録
1. The origin of the seizure discharge evoked in vitro in thin sections obtained from the guinea pig dentate gyrus was studied.
2. The polymorphic layer of the gyrus was not essential for the generation of the discharge but the slice without the granule cell layer could not produce it.
3. The discharge recorded from the pial surface of the slice was composed of a train of positive spikes superposed on a negative slow wave.
4. By inserting the microelectrode into the slice, it was found that the spike took biphasic configuration at intermediate levels and reversed in polarity at the deep layer of the slice.
5. The spikes generated early and late in a discharge train changed their contour at different depths.
6. In contrast with the spike, the surface slow wave had no counterpart in the deep layer.
7. It was concluded that the spike represented the action potential generated in the granule cell body and it was conducted along the principal dendrite. This conduction was blocked at some distance from the cell body.
