Fig. 2: Effects of the 5-HT1B receptor antagonist, SB224289, alone or in combination with zolmitriptan.

There were no main effects nor interactions with sex 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 (0.7 5mg/kg, i.v.) was available for 1h followed by a low dose of cocaine (0.075mg/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 = 20–28/dose) were pretreated 30min prior to the start of the test sessions with SB224289 (3.2–10 mg/kg, s.c.) followed by either vehicle or zolmitriptan (5.6 mg/kg, s.c.) 15 min later. Pound sign (#) represents a difference between low and high cocaine dose, asterisks (*) represent adifference from vehicle, and double dagger (‡) represents difference from zolmitriptan alone (p < 0.05).