AMIRIDINE (NIK-247) AND CEREBROCRAST IN THE ALLEVIATION OF CHOLINERGIC LESION-INDUCED LEARNING DEFICIT IN MALE-RATS

Learning of the male rats was impaired by injecting ethylcholine aziri dinium (AF64A) bilaterally into the basal magnocellular nuclei of Meyn ert. The performance of the rats in a passive avoidance test and in a one-way active avoidance test was significantly improved by giving a n ovel acetylcholinesterase inhibitor, amiridine (NIK-247; o-2,3,5,6,7,8 -hexahydro-1H-cyclopenta(b)-quinoline monohydrate hydrochloride) after each learning session but not when the drug was given before the sess ions. Cerebrocrast, an antagonist of L-type calcium channels, was not effective in either case. Rather it worsened the learning results when given after the sessions of the active avoidance test. The conclusion s in the passive avoidance test were hampered by the observed inconsis tent effects of cholinotoxin. (C) 1993 Wiley-Liss, Inc.