Decreased forebrain [35S]TBPS binding and increased [3H]muscimol binding in rats that do not develop stress-induced behavioral depression

Robert C. Drugan, Steven M. Paul, Jacqueline Crawley

Research output: Contribution to journalArticle

31 Scopus citations


Recent evidence suggests that anxiety and its biological concomitants may be involved in the pathophysiology of depression. In the present study, the in vitro radioligand binding of [3H]flunitrazepam, [3H]muscimol and [35S]t-butylbicyclophosphorothionate (TBPS) sites on the benzodiazepine /GABA chloride ionophore receptor complex (BGRC) was examined using the learned helplessness paradigm. Only rats which did not develop the syndrome showed a significant increase in [3H]muscimol binding in cerebral cortex and a decrease in [35S]TBPS binding in cerebral cortex and hippocampus in comparison to naive controls. For both ligands, this represented a change in Bmax rather than a change in affinity. Adrenalectomy had no impact on these alterations indicating that critical endogenous factors are not manufactured by the adrenal glands. These findings suggest that the BGRC in the forebrain may be a site mediating the 'coping' ability of rats that do not develop the learned helplessness syndrome. The possible involvement of neurosteroids in the effect is discussed.

Original languageEnglish (US)
Pages (from-to)270-276
Number of pages7
JournalBrain Research
Issue number2
StatePublished - Dec 24 1993
Externally publishedYes



  • Anxiety
  • Benzodiazepine
  • Chloride channel
  • Coping behavior
  • Depression
  • GABA
  • Learned helplessness
  • Receptor
  • Shuttlebox escape learning

ASJC Scopus subject areas

  • Neuroscience(all)

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