Korean J Physiol Pharmacol.  2011 Jun;15(3):163-169. 10.4196/kjpp.2011.15.3.163.

Direct Corticosteroid Modulation of GABAergic Neurons in the Anterior Hypothalamic Area of GAD65-eGFP Mice

• Shin SY
• Han TH
• Lee SY
• Han SK
• Park JB
• Erdelyi F
• Szabo G
• Ryu PD

• KMID: 1448920
• DOI: http://doi.org/10.4196/kjpp.2011.15.3.163

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 chi2-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.

Keyword

Paraventricular nucleus; Glucocorticoid receptors; Burst firing; Single cell RT-PCR; Slice patch clamp

MeSH Terms

Animals
Anterior Hypothalamic Nucleus
Brain
Corticosterone
Fires
GABAergic Neurons
Mice
Mice, Transgenic
Mifepristone
Neurons
Paraventricular Hypothalamic Nucleus
Plastics
Receptors, Glucocorticoid
Receptors, Mineralocorticoid
Receptors, Steroid
RNA, Messenger
Spironolactone
Synaptic Transmission
Corticosterone
Mifepristone
Plastics
RNA, Messenger
Receptors, Glucocorticoid
Receptors, Mineralocorticoid
Receptors, Steroid
Spironolactone