Expression of GABA(A) receptor alpha5 subunit-like immunoreactivity in human hippocampus

To investigate the distribution of GABA(A) receptor alpha5 subunit expression in brain, polyclonal antisera were raised, characterised and applied to human and rat brain sections. The resultant antibodies detected a major band of 53 kDa in sodium dodecyl sulphate-polyacrylamide gel electrophoresis immunoblots. Abundant immunostaining was demonstrated in the hippocampal formation in multiple cell types, although predominantly in pyramidal neurons. These data are supportive of GABA-ergic involvement in cognition, and suggest that this influence may be mediated through receptors containing the alpha5 subunit.