Intraaccumbens baclofen selectively enhances feeding behavior in the rat

Intraaccumbens infusions of the GABA, agonist baclofen are known to stimula te food intake in the rat. The aim of the present study was to evaluate the effects of baclofen infusion on nonfood-related chewing and on the consump tion of a palatable fluid. Rats were bilaterally infused with baclofen (188 ng in 1 mu L) or saline, rind tested in a situation in which food was avai lable in one or two locations and wood blocks might also be present. Baclof en-infused animals showed no enhancement of chewing directed at the wood bl ocks, but showed increased food consumption regardless of food location. In a second, separate test we recorded the microstructural parameters for dri nking of a palatable glucose/saccharin mixture. Baclofen infusion had no ef fect on overall intake, although bout size was reduced and the number of bo uts was increased. These data confirm that baclofen-stimulated food intake following accumbens infusion is a robust and substantial phenomenon that ap pears to be selective to solid food. It is likely to result from relatively direct activation of neural circuits for feeding, rather than an indirect facilitation consequent upon changes in taste processings, as has been sugg ested for some other examples of drug-induced hyperphagia. (C) 2000 Elsevie r Science Inc. All rights reserved.