Fos and nitric oxide synthase in rat brain with chronic mesostriatal dopamine deficiency: effects of nitroglycerin and hypoxia

We found sustained proto-oncogene c-fos expression in neurons of the lateral and medial neostriatum and suppression of this expression in nitric oxide synthase (NOS)-containing cells within the islands of Calleja after lesions of the dopaminergic mesostriatal system induced by 6-hydroxydopamine. Systemic administration of nitroglycerin (NTG) or mild hypoxia resulted in a decreased of c-fos expression in the dorsolateral part of the denervated neostriatum. However, in other brain structures NTG or mild hypoxia evoked sustained c-fos expression in NOS-containing neurons and in the sources catecholaminergic projections involved in the control of cardiovascular function. We propose that the administration of NTG, an NO donor, or hypoxia partially attenuate the consequences of an excessively increased glutamate level in the denervated neostriatum which are manifest in high level of c-fos expression. (C) 2002 Elsevier Science Ltd. All rights reserved.