Cortical layer III pyramidal dendritic morphology normalizes within 3 weeks after kindling and is dissociated from kindling-induced potentiation

This experiment examined the effect of a 3-week rest after electrical kindl ing on kindling-induced potentiation and the morphology of frontal (Fr1) ne ocortical layer III pyramidal cell dendrites in both male and female rats, Repeated elicitation of afterdischarge resulted in an increase in the sever ity of the behavioural seizures and afterdischarge duration. The late compo nent of the transcallosal evoked responses was significantly larger 1 and 2 1 days following the last kindling session in both male and female rats. An alysis of the Golgi-Cox impregnated pyramidal cell dendrites indicated no s ignificant difference in the amount of apical and basilar dendritic, branch ing, length, and spine density in both male and female rats, relative to th eir respective control groups, 21 days following the last kindling session. There was, however, one exception, the male group showed a significant inc rease in apical spine density. The persistent expression of kindling-induce d potentiation appears to be dissociated from the renormalized pyramidal ce ll dendritic morphology. (C) 2001 Elsevier Science B.V. All rights reserved .