Fig. 2.
Effects of the GABAB receptor agonist baclofen (left) and GHB (right) in pigeons trained to discriminate between 100 mg/kg rac-BHFF and vehicle using a two-key food-reinforced procedure. Baclofen and GHB were tested alone (solid circles), together with the GABAB receptor antagonist CGP35348 (320 mg/kg; open squares), and together with the GABAB receptor positive modulator rac-BHFF (10 mg/kg; solid squares). Stars indicate mean rates of responding that were significantly (P < 0.05) different from control. See Fig. 1 for other details.