Acute kindling: discrepancy between lengthening of after-discharge duration and increase of field EPSP evoked in...

For studies on acute kindling that signifies the progressive changes in various epileptiform discharges produced with repeated electrical stimulations within a brief time span in acute experiments, changes in field EPSP and IPSP evoked in the unilateral visual cortex of rabbits by single shocks to the adjacent visual region were serially observed during and after kindling produced with a 15-minute interval stimulation repeatedly applied to the same visual cortex. Eventually, both the field EPSP and IPSP in the primary kindled site were progressively potentiated at each postictal or interictal stage during the acute kindling, and these potentiations lasted for hours allowed for acute experiments. However, a clear discrepancy was observed between the increase in the field EPSP and the lengthening of the after-discharge duration reflecting a progressive development of epileptiform discharges in acute kindling. These results suggest that long-term potentiation (LTP) has no parallel correlation to kindling development, although there is no denying the fact that LTP may be at least partly responsible for kindling development.