The effects of motivational and emotional factors in glutamate release in the nucleus accumbens of the rat brain during food consumption.

Studies on male Sprague-Dawley rats using intracerebral dialysis and high-performance liquid chromatography with electrochemical detection showed that consumption of fold with an attractive taste was accompanied by decreases in glutamate levels in the intercelular space of the nucleus accumbens, whose depth and duration depended on food deprivation. It was only in deprived animals that food consumption in conditions of presentation of a conditioned sound signal previously combined with electrocutaneous stimulation of the paws led to increases in intercellular glutamate levels in this structure. Isolated presentation of the aversion-relevant conditioned stimulation did not elicit changes in intercellular glutamate levels. These data suggest cooperativity in the actions of motivational and emotional factors in controlling glutamate release into the intercellular space of the nucleus accumbens during food consumption.