Table 3.

Effects of voluntary ethanol consumption on the abundance of the δ subunit of the GABA_A receptor in various regions of the hippocampus in group-housed or socially isolated rats.

	Group-housed (% increase)	Isolated (% increase)
CA1
Stratum oriens	46 ± 2^a	34 ± 2^a
Pyramidal layer	54 ± 3^a	43 ± 1^a
Stratum radiatum	33 ± 2^a	30 ± 2^a
Stratum lacunosum-moleculare	36 ± 3^a	22 ± 3^a
CA3
Stratum oriens	51 ± 5^a	14 ± 2
Pyramidal layer	79 ± 4^a	27± 1^a
Stratum radiatum	42 ± 2^a	12 ± 3
Dentate gyrus
Molecular layer	33 ± 3^a	26± 2^a
Granular layer	46 ± 3^a	15 ± 1^a
CA4	43 ± 6^a	30 ± 2^a

Rats were housed in groups or in isolation for 30 days immediately after weaning. Isolated or group-housed rats had 24-hour access for 30 days to two bottles, one containing water and the other containing either ethanol (6, 10, or 20%) or water. The hippocampus was then subjected to immunohistochemical staining for determination of the abundance of the δ subunit as described (Serra et al., 2006). Data are expressed as percentage increase in subunit expression for the animals with access to ethanol relative to the corresponding values for those exposed only to water and are means ± SEM of values from six animals for each experimental group.

P < 0.05 versus respective water-only group.