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 aziridinium (AF64A) bilaterally into the basal magnocellular nuclei of Meynert. The performance of the rats in a passive avoidance test and in a one-way active avoidance test was significantly improved by giving a novel acetylcholinesterase inhibitor, amiridine (NIK-247; 9-amino-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 sessions. 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 conclusions in the passive avoidance test were hampered by the observed inconsistent effects of cholinotoxin. © 1993 wiley-Liss, Inc.