Effects of 5,7–Dihydroxytryptamine Lesions of the Prefrontal Cortex on Consumption of Sucrose-Ethanol Solutions: Relationship to Prefrontal Monoamines

Thirty adult male Wistar rats received 8 μg bilaterally of 5,7–dihy-droxytryptamine into the medial prefrontal cortex (mPFC). Rats were then trained, via a sucrose fading paradigm, to consume increasing concentrations of alcohol. After death, dopamine (DA), norepineph-rine (NE), serotonin (5–HT), and their metabolites were measured in the mPFC, nucleus accumbens (NA), and raphe nucleus. The le-sioned group demonstrated a reduction in 5–hydroxyindoleacetic acid (5–HIAA), DA, and NE in the mPFC ( p < 0.05), and a trend toward reduction of 5–HT in the NA. In comparison with controls, lesioned animals consumed less of all solutions containing sucrose and alcohol. On regression analyses, monoamines in the mPFC (i.e., 5–HIAA, dihydrophenylacetic acid and NE) predicted consumption of the 5% ethanol solution ( p = 0.00S), 10% ethanol solution ( p = 0.0006), and the 5% sucrose solutions ( p = 0.0006), but not the 20% sucrose solutions. In each case, monoamine levels were positively correlated with consumption. No relationships were seen between monoamine levels in the NA and raphe, and in consummatory behavior.