Spike-dependent depolarizing afterpotentials contribute to endogenous bursting in gonadotropin releasing hormone neurons

M. C. Kuehl-Kovarik, K. M. Partin, R. J. Handa, F. E. Dudek

Research output: Contribution to journalArticle

28 Scopus citations

Abstract

Pulsatile secretion of gonadotropin releasing hormone in mammals is thought to depend on repetitive and prolonged bursts of action potentials in specific neuroendocrine cells. We have previously described episodes of electrical activity in isolated gonadotropin releasing hormone neurons, but the intrinsic mechanisms underlying the generation of spike bursts are unknown. In acutely isolated gonadotropin releasing hormone neurons, which had been genetically targeted to express enhanced green fluorescent protein, current pulses generated spike-mediated depolarizing afterpotentials in 69% of cells. Spike-dependent depolarizing afterpotentials could evoke bursts of action potentials that lasted for tens of seconds. Brief pulses of glutamate (as short as 1 ms), which simulated excitatory postsynaptic potentials, also triggered spike-mediated depolarizing afterpotentials and episodic activity. These data indicate that spike-dependent depolarizing afterpotentials, an endogenous mechanism in gonadotropin releasing hormone neurons, likely contribute to the episodic firing thought to underlie pulsatile secretion of gonadotropin releasing hormone. Furthermore, fast excitatory postsynaptic potentials mediated by glutamate can activate this intrinsic mechanism.

Original languageEnglish (US)
Pages (from-to)295-300
Number of pages6
JournalNeuroscience
Volume134
Issue number1
DOIs
StatePublished - Jul 19 2005
Externally publishedYes

Keywords

  • DAP
  • EPSP
  • Electrophysiology
  • Episodic activity
  • Glutamate
  • GnRH

ASJC Scopus subject areas

  • Neuroscience(all)

Fingerprint Dive into the research topics of 'Spike-dependent depolarizing afterpotentials contribute to endogenous bursting in gonadotropin releasing hormone neurons'. Together they form a unique fingerprint.

  • Cite this