The action of arecoline on retrieval and memory storage evaluated in the staircase maze

Rats were trained to run on a staircase stopping on the 3rd, 6th, 9th, and 12th steps (correct responses). Stopping on any other step was considered an error. Acute administration of 0.5 mg/kg of arecoline 15 min before the trial improved behavior and 3.5 mg/kg of arecoline caused a reduction of correct responses. An interruption of the daily training for 20 days caused a 15% reduction of correct responses in control animals. Chronic administration of arecoline during the first 15 days of a no-training period caused an increase of errors only at 3.5 and 8 mg/kg/day. The interpretation of these results is that arecoline improves the retrieval process and accelerates the spontaneous decay of memory. The increase of correct responses after the acute administration of 0.5 mg/kg of arecoline was not evident in rats treated for 15 days with arecoline 6.5 mg/kg/day. These results suggest that arecoline improves retrieval only in the absence of tolerance development.