Timeline of experimental manipulations. Ovariectomized female rats were injected with the cannabinoid type 1 receptor inverse agonist, AM251, or vehicle (veh) followed by estradiol (E) or oil, on days 1, 2, 5, and 6 (n = 14–19 per group). Cocaine (Coc) was injected on days 3–7 and locomotor activity was assessed on day of the first and fifth Coc injections (Test 1 and Test 5 respectively). 24 hrs after the final Coc injection a subset of females that were tested for behavior were sacrificed for DiI labeling.