Fig. 1.

Effects of acute injections of tamoxifen on autoshaped-operant responding on acquisition day 1 (closed circles) and retention day 2 (open squares) in male, Swiss-Webster mice. Ordinates: adjusted mean latency (latency to the tenth reinforcer [L10]−latency to the first reinforcer [L1]) in seconds (left); total number of nose pokes in the center, reinforced dipper well per second (middle); and total number of nose pokes in the non-reinforced right or left nose poke holes per second (right). Total number of mice tested on day 1/number of mice completing ten reinforcers on day 1 and therefore included in the day 2 latency measures: saline [12/11] and tamoxifen 3.2 mg/kg [6/6], 32 mg/kg [11/10], and 100 mg/kg [6/0]. Abscissa: dose in milligrams per kilogram administered i.p. Points above Sal are the effects of saline alone. Vertical lines represent SEM. *p<0.05 relative to saline responding.p̂<0.05 for day 1 vs. day 2