Fig. 3. Effects of the 5-HT1D receptor antagonist, BRL15572, alone or in combination with zolmitriptan.

There were no interaction effects with sex and pretreatment and therefore the data are collapsed across sex. Data are expressed as the mean (±SEM) for cocaine infusions (a, e), intake (b, f), and active (c, g) and inactive (d, h) lever responses during test sessions where the training dose of cocaine (0.75 mg/kg, i.v.) was available for 1h followed by a low dose of cocaine (0.075 mg/kg, i.v.) available for 1h. Horizontal lines correspond to the mean of vehicle pretreatment under the low (dashed line) and training (solid line) cocaine doses tested. Rats (n = 18–28/dose) were pretreated 30min prior to the start of the test sessions with BRL15572 (0.3–3 mg/kg, i.p.) followed by either vehicle or zolmitriptan (5.6 mg/kg, s.c.) 15min later. Pound sign (#) represents a difference between low and high cocaine dose, and asterisks (*)represent a difference from vehicle (p < 0.05).