Down-regulation of neurosteroid biosynthesis in corticolimbic circuits mediates social isolation-induced behavior in mice.

ABSTRACT: Allopregnanolone (ALLO), synthesized by pyramidal neurons, is a potent positive allosteric modulator of the action of GABA at GABA(A) receptors expressing specific neurosteroid binding sites. In the brain, ALLO is synthesized from progesterone by the sequential action of two enzymes: 5alpha-reductase type I (5alpha-RI) and 3alpha-hydroxysteroid dehydrogenase (3alpha-HSD). In the cortex, hippocampus, and amygdala, these enzymes are colocalized in principal glutamatergic output neurons [Agís-Balboa RC, Pinna G, Zhubi A, Maloku E, Veldic M, Costa E, Guidotti A (2006) Proc Natl Acad Sci USA 103:14602-14607], but they are not detectable in GABAergic interneurons. Using RT-PCR and in situ hybridization, this study compares 5alpha-RI and 3alpha-HSD mRNA brain expression levels in group housed and

SUBMITTER: Agis-Balboa RC 

PROVIDER: S-EPMC2141846 | biostudies-literature | 2007 Nov

REPOSITORIES: biostudies-literature