Chunk #30 — 4. Selectively bred high alcohol-consuming rat lines and their phenotypic characteristics — 4.3. High alcohol-drinking and low alcohol-drinking rats
Regarding neurochemical correlates, HAD1 rats have lower 5-HT and/or 5-HIAA levels in cortical and limbic regions than LAD1 rats (Gongwer et al., 1989). HAD rats have lower levels of DA and its me-tabolites (DOPAC and HVA) in the Acb and anterior striatum, compared with LAD rats (Gongwer et al., 1989). Also, Katner and Weiss (2001) compared rats from the HAD1 and LAD1 lines on the extracellular concentrations of DA in the Acb and found that, as with AA vs. ANA rats and P vs. Wistar rats, extracellular DA levels predict high ethanol preference with rats genetically predisposed for high ethanol consumption having a greater DA response following ethanol exposure (Katner and Weiss, 2001; Weiss et al., 1993). Higher densities of GABAergic terminals are found in the Acb of ethanol-naive HAD rats, compared with their LAD counterparts (Hwang et al., 1990). Similar to P rats, reduced levels of NPY-immunoreactivity in the central amygdala are found in HAD rats, compared with LAD rats (Hwang et al., 1999). Thus, the similar differences observed in the 5-HT, DA, GABA and NPY neuronal systems between
