title: Direct Corticosteroid Modulation of GABAergic Neurons in the Anterior Hypothalamic Area of GAD65-eGFP Mice.
abstract: Corticosterone is known to modulate GABAergic synaptic transmission in the hypothalamic paraventricular nucleus. However, the underlying receptor mechanisms are largely unknown. In the anterior hypothalamic area (AHA), the sympathoinhibitory center that project GABAergic neurons onto the PVN, we examined the expression of glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) of GABAergic neurons using intact GAD65-eGFP transgenic mice, and the effects of corticosterone on the burst firing using adrenalectomized transgenic mice. GR or MR immunoreactivity was detected from the subpopulations of GABAergic neurons in the AHA. The AHA GABAergic neurons expressed mRNA of GR (42%), MR (38%) or both (8%). In addition, in brain slices incubated with corticosterone together with RU486 (MR-dominant group), the proportion of neurons showing a burst firing pattern was significantly higher than those in the slices incubated with vehicle, corticosterone, or corticosterone with spironolactone (GR-dominant group; 64 vs. 11~14%, p< 0.01 by χ(2)-test). Taken together, the results show that the corticosteroid receptors are expressed on the GABAergic neurons in the AHA, and can mediate the corticosteroid-induced plasticity in the firing pattern of these neurons. This study newly provides the experimental evidence for the direct glucocorticoid modulation of GABAergic neurons in the AHA in the vicinity of the PVN.
authors.affiliation: Laboratory of Veterinary Pharmacology, College of Veterinary Medicine and Research Institute for Veterinary Science, Seoul National University, Seoul 151-742, Korea.
authors.forename: Seung Yub
authors.initials: SY
authors.lastname: Shin
authors.forename: Tae Hee
authors.initials: TH
authors.lastname: Han
authors.forename: So Yeong
authors.initials: SY
authors.lastname: Lee
authors.forename: Seong Kyu
authors.initials: SK
authors.lastname: Han
authors.forename: Jin Bong
authors.initials: JB
authors.lastname: Park
authors.forename: Ferenc
authors.initials: F
authors.lastname: Erdelyi
authors.forename: Gabor
authors.initials: G
authors.lastname: Szabo
authors.forename: Pan Dong
authors.initials: PD
authors.lastname: Ryu