Figure 5.

Caudolateral SNr lesions also reduce withdrawal severity after repeated ethanol administration. a, Bilateral caudolateral SNr-lesioned and sham-lesioned D2 mice were scored for baseline HICs. Lesioned mice (n = 12) and one group of sham-lesioned mice (n = 11) received three injections of 4 g/kg ethanol at hour 0, 8, and 20. In the second group of sham-lesioned mice, the first and second injections were replaced with saline, and ethanol was administered only once at hour 20 (n = 6). All mice were tested for HICs hourly beginning at hour 22 and through hour 34. Data represent the mean raw scores ±SEM for baseline and postethanol HICs. b, Repeated episodes of ethanol intoxication and withdrawal significantly enhanced ethanol withdrawal severity (AUC, corrected for baseline HIC scores) compared with acute ethanol withdrawn animals (p < 0.05). Mice with bilateral caudolateral SNr lesions displayed significantly less severe ethanol withdrawal than sham-lesioned animals after repeated episodes of ethanol intoxication and withdrawal (p = 0.001). *p < 0.05; **p < 0.005.