in the alcohol preferring (P) and the high alcohol drinking (HAD1 and HAD2) selected lines versus the non-alcohol preferring (NP) and the low alcohol drinking (LAD1 and LAD2) selected lines. The P and NP lines were derived from outbred Wistar rats, while the HAD and LAD lines were derived from an eight-strain rat HS. Acute withdrawal sensitivity was measured using the acoustic startle response. The P/NP and HAD1/LAD1 lines gave the expected acute withdrawal response—higher in the NP and LAD1 lines. However, there was no significant difference between the HAD2 and LAD2 lines. In a separate study and when white noise rather than a tone was used as the stimulus, the P/HAD1/HAD2 lines exhibited an enhanced withdrawal-induced startle response, whereas no change was found in the NP/LAD1/LAD2 lines (Chester et al. 2004). Recently, Chester and Barrenha (2007) examined the acute withdrawal-induced startle response in the high alcohol preferring (HAP1/HAP2) and low alcohol preferring (LAP1/LAP2) mouse lines, which were selectively bred from HS/Ibg mice (Grahame et al. 1999). Here, the male LAP lines, when compared with the male HAP lines, showed a withdrawal-induced suppression of the startle response; the effect in females was line dependent.
