DIRECT COMPARISON OF COGNITIVE FACILITATION BY PHYSOSTIGMINE AND TETRAHYDROAMINOACRIDINE IN 2 PRIMATE MODELS

Cognitive facilitation by physostigmine and tetrahydroaminoacridine (THA) was compared in two primate models. Disruption of spatial delayed response performance by scopolamine (0.03 mg/kg) was fully reversed by coadministration of 5 doses of physostigmine in the range 0.03-0.08 mg/kg, but by only one dose (4.0 mg/kg) of THA; partial reversal of some effects of scopolamine was observed at 1 and 3 mg/kg of THA. Visual recognition memory was enhanced following treatment with 4 doses of physostigmine in the range 0.001-0.03 mg/kg. The effect of THA across the group of animals was not significant but performance tended to improve using a dose of 0.8 mg/kg. Our findings indicate that THA does not have a superior profile to physostigmine as a cognitive enhancer in primates. © 1990.