N. Villeneuve et al., Neonatal seizures induced persistent changes in intrinsic properties of CA1 rat hippocampal cells, ANN NEUROL, 47(6), 2000, pp. 729-738
We investigated the effects of repeated early-life seizures induced by flur
othyl inhalation on intrinsic membrane properties of hippocampal pyramidal
neurons from young rats (postnatal day 15-20). Intracellular recordings of
CA1 and CA3 pyramidal neurons from flurothyl-treated and control rats revea
led no significant differences in resting membrane potential, input resista
nce, membrane time constant, and action potential characteristics. In CA1 p
yramidal cells from flurothyl-treated rats, the spike frequency adaptation
and afterhyperpolarizing potential following a spike train were markedly re
duced when compared with controls. In contrast, no significant alterations
in the firing properties of CA3 pyramidal neurons were found. It is conclud
ed that neonatal seizures lead to persistent changes in intrinsic membrane
properties of CA1 pyramidal neurons. These alterations are consistent with
an increase in neuronal excitability and may contribute to the behavioral d
eficit and epileptogenic predisposition observed in rats that experienced r
epeated neonatal seizures.