Reciprocal homeostatic reactions to chronic excitatory synaptic receptor inactivation in developing cerebral cortex networks

Abstract

Chronic blockade of actively excitatory glutamatergic synaptic receptors in co-cultured organotypic rodent neocortex explants leads to a compensatory up-regulation of otherwise inactive input channels so as to maintain almost normal levels of ongoing bursts of action potentials. We report here that this homeostatic return of spontaneous (now kainate receptor driven) firing is accompanied by a reciprocal down-regulation of blocked AMPA and NMDA receptors, such that the developing cortical network is protected against becoming hyperactive when those synaptic inputs are again able to transmit normally.