Rats were exposed to ethanol prenatally and euthanized on postnatal (P) 0, P3, P6, P12, P24, or P30. The volume (top), the neuronal packing density (middle), and the total number of neurons (bottom) in the VB were quantified. Each point (solid circles identify data for controls; open circles signify data for ethanol-treated rats) represents the means of five rats, each rat being from a different litter. T-bars show standard errors of the means. * denotes significant difference between Ct- and Et-treated groups. Numbers describe significance (p<0.05) within Ct-treatment group, letters are used for Et-treated animals. 1, different to all other ages; 2, different to P21 and P30; 3, different to P3, P6, and P30. a, different to all other ages; b, different to P0, P3, P6, and P30; c, different to P12, P21, and P30; d, different to P3 and P6.