Bicarbonate contributes to GABAA receptor-mediated neuronal excitation in surgically resected human hypothalamic hamartomas

Do Young Kim, Kristina A. Simeone, John F. Kerrigan, Jong M. Rho

Research output: Contribution to journalArticle

16 Citations (Scopus)

Abstract

The role of bicarbonate (HCO3-) in GABAA receptor-mediated depolarization of human hypothalamic hamartoma (HH) neurons was investigated using cellular electrophysiological and calcium imaging techniques. Activation of GABAA receptors with muscimol (30 μM) provoked neuronal excitation in over 70% of large (18-22 μM) HH neurons in HCO3- buffer. Subsequent perfusion of HCO3--free HEPES buffer produced partial suppression of muscimol-induced excitation. Additionally, 53% of large HH neurons under HCO3--free conditions exhibited reduced intracellular calcium accumulation by muscimol. These results suggest that HCO3- efflux through GABAA receptors on a subpopulation of large HH neurons may contribute to membrane depolarization and subsequent activation of L-type calcium channels.

Original languageEnglish
Pages (from-to)89-93
Number of pages5
JournalEpilepsy Research
Volume83
Issue number1
DOIs
StatePublished - Jan 2009

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GABA-A Receptors
Bicarbonates
Muscimol
Neurons
Buffers
HEPES
Calcium
L-Type Calcium Channels
Perfusion
Membranes
Hypothalamic hamartomas

All Science Journal Classification (ASJC) codes

  • Clinical Neurology
  • Neurology

Cite this

Bicarbonate contributes to GABAA receptor-mediated neuronal excitation in surgically resected human hypothalamic hamartomas. / Kim, Do Young; Simeone, Kristina A.; Kerrigan, John F.; Rho, Jong M.

In: Epilepsy Research, Vol. 83, No. 1, 01.2009, p. 89-93.

Research output: Contribution to journalArticle

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