Glucocorticoids are modulators of GABAA receptors in brain

Brain Res. 1985 Jul 22;339(1):178-82. doi: 10.1016/0006-8993(85)90641-9.


Modulation of binding of [3H]muscimol, a GABAA receptor agonist, by natural and synthetic glucocorticoids was investigated in crude synaptosomal membranes and in brain sections of rat. In adrenalectomized (Adx) rats, muscimol binding was reduced by 30-50% in cerebral cortex, cerebellum, thalamus and hippocampus, as compared to sham-operated controls. This decrease was due to reduced binding affinities of GABA receptors for muscimol. In contrast muscimol binding was increased by 38% in the hypothalamus and did not change in the pons-medulla after Adx. Nanomolar concentrations of corticosterone and pregnenolone-sulfate, but not dexamethasone, enhanced muscimol binding in brain regions that were characterized by reduced binding following Adx. This steroid-induced increase in muscimol binding was due to enhanced affinities of GABA receptors.

Publication types

  • Comparative Study

MeSH terms

  • Adrenalectomy
  • Animals
  • Brain / physiology*
  • Corticosterone / pharmacology
  • Dexamethasone / pharmacology
  • Glucocorticoids / physiology*
  • Muscimol / metabolism
  • Pregnenolone / pharmacology
  • Rats
  • Rats, Inbred Strains
  • Receptors, GABA-A / drug effects
  • Receptors, GABA-A / physiology*


  • Glucocorticoids
  • Receptors, GABA-A
  • pregnenolone sulfate
  • Muscimol
  • Pregnenolone
  • Dexamethasone
  • Corticosterone