REPEATED SWIM-STRESS REDUCES GABA-A RECEPTOR ALPHA-SUBUNIT MESSENGER-RNAS IN THE MOUSE HIPPOCAMPUS

The effects of brief repeated swim stress on the expression of GABA(A) receptor alpha1 subunit mRNAs was investigated in the mouse. Adult ma le mice were exposed to repeated brief (10 min) swim-stress once daily for 7 or 14 days and the levels of GABA(A) receptor a subunit mRNAs w ere quantified in the hippocampus 24 h after the last session by North ern analysis. Repeated swim stress for 14 days resulted in a 47.3% +/- 6.5 and 39.8% +/- 7.6 decrease in the levels of the 4.8 kb and 4.4 kb GABA(A) receptor a 1 subunit mRNAs, respectively. While there was a t rend toward a reduction in the level of GABA(A) receptor al subunit mR NAs following 7 days of repeated swim stress, the latter did not reach statistical significance. In contrast, no significant alterations in the levels of glutamic acid decarboxylase or beta-actin mRNAs were obs erved at either time point. The reduction in GABA(A) receptor al subun it mRNAs following repeated swim stress may underlie similar alteratio n(s) in hippocampal GABA(A) receptor density previously observed follo wing repeated swim stress.