APOPTOTIC NEURON DEATH IN RAT SUBSTANTIA-NIGRA INDUCED BY STRIATAL EXCITOTOXIC INJURY IS DEVELOPMENTALLY DEPENDENT

We have previously observed that an axon-sparing lesion of the striatu m during development is associated with an induction of apoptotic cell death in the substantia nigra (SN). We have postulated that the induc ed death is due to a loss of striatum-derived trophic support. In othe r paradigms of neural development, it is often found that a need for t rophic support is primarily observed only during a critical developmen t period. We have therefore examined the time course for early striata l lesion to induce cell death in substantia nigra. We find that induct ion of apoptotic cell death is largely restricted to the first 2 postn atal weeks. After that time, induction of death in SN pars compacta ab ates. In SN pars reticulata, apoptotic death also abates, but by postn atal day 28, a non-apoptotic morphology of death appears. Thus, induce d apoptotic death in SN is restricted to a critical developmental peri od. Copyright (C) 1996 Elsevier Science Ireland Ltd.