Expression and estrogen regulation of brain-derived neurotrophic factor gene and protein in the forebrain of female prairie voles

Brain-derived neurotrophic factor (BDNF) has been linked to the development , differentiation, and plasticity of the central nervous system. In the pre sent study, we first used a highly specific affinity-purified antibody and a cRNA probe to generate a detailed mapping of BDNF immunoreactive (BDNF-ir ) staining and mRNA labeling throughout the forebrain of female prairie vol es. Our data revealed that (1) BDNF-ir cells were present essentially in th e brain regions in which BDNF mRNA-labeled cells were found; (2) BDNF-ir fi bers were distributed extensively throughout many forebrain regions; and (3 ) BDNF mRNA was also detected in some thalamic regions in which BDNF-ir fib ers, but not immunostained cells, were present. With few exceptions, the di stribution pattern of BDNF in the vole brain generally resembled the patter n found in rats. In a second experiment, we examined the effects of estroge n on BDNF expression. Ovariectomized prairie voles that were treated with e stradiol benzoate had a higher level of BDNF mRNA labeling in the dentate g yrus and CA3 region of the hippocampus, as well as in the basolateral nucle us of the amygdala, than did ovariectomized voles that were treated with ve hicle. In addition. estrogen treatment increased the density of BDNF-ir fib ers in the lateral septum, dorsolateral area of the bed nucleus of tile str ia terminalis, and lateral habenular nucleus. These data suggest that estro gen may regulate BDNF at the level of gene and protein expression, and thus , BDNF may be in a position to mediate the effects of estrogen on the brain of the prairie vole. (C) 2001 Wiley-Liss, Inc.