Effect of anisodine and other cholinergic drugs on conditioned response of the hippocampal theta rhythm in rabbits

Anisodine is a muscarinic anticholinergic alkaloid from Anisodus tanguticus (Maxim) Pascher or Scopolia tangutica (Maxim) in our institute. It is similar to scopolamine both in chemical structure and in pharmacological prorerties. In this paper effects of anisodine and 4 other cholinergic drugs on learning and memory were studied using conditioned response of the hippocampal θ-rhythm in rabbits. Anisodine (0.25-1.0mg/kg) and scopolamine (0.1 mg/kg) impaired markedly the processes of acquisition, consolidation and retrieving of memory. The actions of anisodine on learning and memory appeared to be specific. The time span for consolidation of memory was less than 3 h determined by the administration of anisodine shortly after training. There were iv 1.0 mg/kg, qd ×3 d. Physostigmine 0.1mg/kg and oxotremorine 5 μg/kg Improved learning and memory behaviors significantly. Our results convincingly support the view that normal function of the cholinergic system, especially the muscarinic system, is necessary for memory formation in the mammalian brain.