dose motor impairing effects of ethanol more readily than NP rats (Waller et al., 1983), and tolerance persists longer in the P than NP rat (Gatto et al., 1987). In another study, repeated intraperitoneal (i.p.) injections of 1 g/kg ethanol produced differential changes in dopamine and serotonin neurotransmission in the ACB of P, NP and Wistar (W) rats (Smith and Weiss 1999). In addition, using the oscillating bar task, NP rats were more sensitive than P rats to the motor impairing effects of 1 g/kg i.p. ethanol; with repeated ethanol injections, the performance of the NP rats on the oscillating bar task improved, suggesting the development of tolerance (Bell et al., 2001). Overall, these results suggested that ethanol exposure produced differential neuronal alterations in the CNS between P and NP rats.
