Figure 5.

Gabapentin decreases ethanol intake. A, The data reflect mean (±SEM) “ethanol lever presses” or “operant ethanol responses” (grams per kilogram) by rats either exposed to chronic ethanol vapor (dependent rats; black bars; n = 11) or not exposed to ethanol vapor (nondependent rats; white bars; n = 14) after pretreatment with gabapentin. Rats were tested for 30 min operant ethanol self-administration 2 h after removal from vapor chambers and 30 min after injection of various doses (0, 5, 10, 30, or 120 mg/kg, i.p.; all rats injected with all doses of gabapentin in a Latin-square design) of gabapentin. Dependent rats consumed significantly more ethanol than nondependent rats, an effect that was blocked by the three highest doses (10, 30, and 120 mg/kg) of gabapentin. The two highest doses (30 and 120 mg/kg) of gabapentin suppressed ethanol intake in dependent rats relative to saline injection. No dose of gabapentin affected ethanol intake by nondependent rats. *p < 0.05, significant difference from vehicle (0 mg/kg gabapentin) in the same group of rats; ^#p < 0.05, significant difference from nondependent rats injected with the same gabapentin dose. B, Gabapentin did not alter water responding by any group of rats (Fig. 6B) (p > 0.05 in all cases).