Fig. 2.

Effects of the cannabinoid CB₁ agonist AM411 in squirrel monkeys responding under a FR30 schedule of stimulus-shock termination before (open circles) and during (solid circles) chronic treatment with AM411 (1.0 mg/kg per day, i.m.). Abscissa: single AM411 dose, log scale; ordinate (left and right panel): rate of responding as a percentage of control rates. Points are means (± S.E.M.) based on data from three or four monkeys. Open and closed circles above prechronic “V” and chronic “V”, respectively, represent mean control values (100% ± average S.D.) under the FR30 stimulus-shock termination schedule in the five sequential components of the session. Control data for prechronic AM411 are re-plotted from Fig. 1. Dotted line represents mean 100% averaged across session components.