Induction of astrocytic nestin expression by depolarization in rats

Nestin is expressed in central nervous system (CNS) progenitor cells and it s expression in mature cells represents transition to a less differentiated cellular state under cellular stress. This study was performed to corrobor ate the hypothesis that nestin synthesis is induced by depolarization and d ependent on N-methyl-D-aspartate (NMDA)-receptor activation. Depolarization was induced with application of potassium chloride on the exposed rat cort ex and nestin expression was evaluated by immunohistochemistry. Depolarizat ion induced astrocytic nestin expression that was local, or evident in the entire ipsilateral cortex depending on the time of exposure. Nestin express ion was NMDA-receptor-dependent since MK-801 treatment abolished the respon se. Understanding the mechanisms for nestin expression is important since t his protein is expressed in reactive and less differentiated CNS cell state s and also in neural stem cells. Insights into the control of nestin expres sion may also provide means for controlling differentiation of CNS cells ei ther post-trauma/ischemia or in transplantation strategies. (C) 2001 Elsevi er Science Ireland Ltd. All rights reserved.