PROTECTION BY AN ADENOSINE ANALOG AGAINST KAINATE-INDUCED EXTRAHIPPOCAMPAL NEUROPATHOLOGY

1. The glutamate analogue kainic acid produces neuronal damage in the central nervous system. We have reported that analogues of adenosine, such as R-N6-phenylisopropyladenosine (R-PIA) can, at doses as low as 10 mu g/kg IP, prevent the hippocampal damage that follows the systemi c administration of kainate. The present work was designed to examine purine protection against kainate in extrahippocampal regions by using histological methods. 2. The results show that R-PIA, at a dose of 25 mu g/kg IP in rats, can protect against the neuronal damage caused by kainate in the basolateral amygdaloid nuclei, the pyriform cortex and around the rhinal fissure. This protection could be prevented by the simultaneous administration of the Al adenosine receptor antagonist 1, 3-dipropyl-8-cyclopentylxanthine, confirming that the protection invol ved adenosine Al receptors. No protection was observed in the posterio r amygdaloid nuclei or the entorhinal cortex, suggesting the absence o f relevant adenosine receptors or a different mechanism of excitotoxic ity. (C) 1998 Elsevier Science Inc.