Figure 1.

Percent conditioned responses for control (triangles, solid line; n = 13), propranolol (circles, dashed line; 100 μM; n = 12), and Rp-cAMPS (squares, uneven dashed line; 80 nM; n = 5). Paired trials were presented in daily sessions of 50 trials for 6 d. Drugs were infused 5 min prior to training. Control rats showed a progressive increase in percent CRs over days and were significantly different from the other two groups (statistics in the body of the text). The propranolol group also showed significant improvement over days of training but did not reach the same performance level as control rats. The Rp-cAMPS group did not show improvement over days of training.