Fig. 6.
50-kHz USVs, locomotor activity and lever responses (means + SEM) before and after “weekend” cue abstinence during extinction sessions: SA and Y combined. a. Significantly greater cocaine-induced 50-kHz USVs (n =14) were detected on the Mondays following 2 days of cue abstinence (e.g., weekend in home cage only) compared to the 5th day of consecutive extinction sessions (e.g., Fridays). No significant differences were detected in cocaine-naïve animals (n = 11) after identical home cage confinement. b. Cocaine-experienced rats showed significantly greater locomotor activity on Mondays compared to Fridays and compared to saline controls. c. Lever responses in the cocaine animals were significantly greater than saline groups on Friday and Monday sessions, but lever responses were comparable between sessions. ^^ = significantly greater within-treatment effects on Mondays vs. Fridays; p < 0.01; *, ** = significantly greater than saline control condition on same day; p < 0.05 or p < 0.01, respectively.