Figure 5.

Initiating methamphetamine self‐administration prior to concurrent alcohol consumption procedures reduces initial alcohol consumption and preference. (a) Timeline illustrating the schedule of combining the 24‐hour two‐bottle choice procedure and daily 2‐hour self‐administration sessions and extinction sessions. (b) Average number of MA infusions (± SEM; 0.1 mg/kg/100 µl infusion) during each 2‐hour session over the 5 days prior to alcohol consumption and the 10 days concurrent with alcohol consumption (rose shading). (c) Average number of drug‐paired lever presses for each 2‐hour session during the three‐day extinction procedure. Prior self‐administration of methamphetamine reduces (d) preference and (e) intake of 10 percent alcohol during the beginning of the co‐use phase (rose shading) but not during the later days of the co‐use phase. The red symbols indicate significance between MA and saline self‐administration groups on that day (p < 0.05); n = 9–11/group