COMPARISON OF THE BEHAVIORAL AND MORPHOLOGICAL EFFECTS OF COLCHICINE-INDUCED OR NEUTRAL FLUID-INDUCED DESTRUCTION OF GRANULE CELLS IN THE DENTATE GYRUS OF THE RAT

Virtually complete destruction of dentate gyrus granule cells by colch icine injections produced a persistent incapacity to solve spatial pro blems in rats. A topographically more selective but only locally compl ete destruction of granule cells using injections of neutral fluid (NF L) impaired acquisition during the initial stages of Morris water maze testing, thus indicating that limited degeneration of granule cells m ay weakly but significantly alter spatial learning capabilities. A sub amnestic dose (0.08 mg/kg ip) of the NMDA antagonist MK-801 worsened r adial maze performance only in NFL-treated rats, suggesting that there may be a synergistic interaction between NMDA blockade and limited gr anule cell degeneration. (C) 1997 Academic Press.