Fig. 6.

Ketamine time course for 30-mg/kg dose compared with vehicle on DRL 72-s behavior. The “30 ketamine” label reflects the 30 mg/kg ketamine data shown in Fig. 5. The D1, D2, and D7 data refer to reinforcers and total responses made during the 60-minute behavioral session 1, 2, and 7 days after the ketamine dose with the session conducted at the same time of day in each case. The same symbols are used for the vehicle and the effects of ketamine 60 minutes after injection as were used in Fig. 5. The DRL 72-s 1, 2, and 7 days after the 30-mg/kg ketamine injection are displayed by blue circles, blue-green inverted triangles, and blue circles with a black surrounding line, respectively.