Reciprocal homeostatic responses to excitatory synaptic receptor inactivation in developing organotypic cortical networks in vitro.

Chronic blockade of actively excitatory glutamatergic synaptic receptors in co-cultured organotypic rodent neocortex explants rapidly leads to a compensatory sensitization of otherwise inactive input channels so as to maintain ongoing action potential bursts. We report here that the homeostatic return of spontaneous, kainate receptor driven, spike discharges is followed by a reciprocal desensitization of blocked AMPA and NMDA receptors, such that the developing network is protected against becoming hyperactive once full synaptic drive is restored.