EFFECTS OF SDZ ENA-713, NOVEL ACETYL CHOLINESTERASE INHIBITOR, ON LEARNING OF RATS WITH BASAL FOREBRAIN LESIONS

1. The effects of SDZ ENA 713, a novel acetyl cholinesterase inhibitor , on rat learning was studied using a step-down avoidance paradigm. 2. Injection of ibotenic acid into the caudolateral part of the basal fo rebrain(BF) innervating cholinergic neurons to the cerebral cortex, re sulted in an increase in the number of trials required to obtain 300-s econd-latency, and also a decrease in the latency period after attaini ng 300-second-latency. 3. It is shown that the BF-lesioned rats are im paired in both acquisition and retention of learning. 4. Intraperitone al injection of 0.10-0.05 mg/kg/day SDZ ENA 713 to the BF-lesioned rat s showed amelioration of the learning impairment, with a decreased num ber of trials required to obtain 300-second-latency as well as an incr ease in the latency time after repeated training. 5. These results ind icate that SDZ ENA 713 improves acquisition and retention impairment i n BF-lesioned rats, and that this drug may be useful for demented pati ents with cholinergic dysfunction, such as Alzheimer's disease.