Chunk #25 — 4. Selectively bred high alcohol-consuming rat lines and their phenotypic characteristics — 4.2. Alcohol-preferring and alcohol-nonpreferring rats
was found to increase DA overflow above baseline values to a greater extent in the Acb of P rats than in unselected Wistar rats (Weiss et al., 1993). P rats also have reduced numbers of D2 receptors in the VTA and Acb compared to NP rats (McBride et al., 1993a). There are higher densities of GABAergic terminals found in the Acb of ethanol-naive P rats, compared with NP rats (Hwang et al., 1990). In addition, P rats have higher densities of mu-opioid receptors in CNS limbic areas, relative to NP, rats, including the Acb shell and core (McBride et al., 1998). Lower levels of NPY are found in the amygdala, hippocampus, and frontal cortex of P, compared with NP, rats (Ehlers et al., 1998). Similarly, lower levels of CRF are found in the amygdala, hypothalamus, prefrontal cortex, and cingulate cortex of P, compared with NP, rats (Ehlers et al., 1992). It is interesting that despite having low CRF levels, at least relative to NP rats, P rats display autonomic reactivity to ethanol consumption and its associated cues (Bell et al., 2002, 2008b) similar to that observed in alcohol-dependent and -nondependent individuals with a paternal family history of alcoholism (e.g., Brunelle
