[Effect of scopolamine on temporary connection formation and fixation in rats with altered brain noradrenaline...

The locus coeruleus was ablated in rats or a 100 mg/kg dose of disulfiram and a 0.5 mg/kg dose of scopolamine were administered to them. Then a conditioned two-side avoidance reflex was elaborated. The locus coeruleus ablation and administration of disulfiram brought about a nearly equal reduction of noradrenaline (NA) content in the brain. Scopolamine against the background of a low NA level did not change its content. Ablation of locus coeruleus, administration of disulfiram and scopolamine did not prevent the elaboration, fixation and retention of the conditioned defensive reflex. Scopolamine introduced to animal with ablated locus coeruleus while not affecting the elaboration of defensive conditioned two-side avoidance reflex, completely prevented its retention. Administration of scopolamine to animals with a depressed NA synthesis produced a less profound amnesia.