Of neurons and networks: Control of firing in hypothalamic gonadotropin releasing hormone (GnRH) neurons: Insights from dynamic current clamping and compartmental modeling

Kelly J. Suter
Emory University

(April 18, 2006 3:30 PM - 4:30 PM)

Of neurons and networks: Control of firing in hypothalamic gonadotropin releasing hormone (GnRH) neurons: Insights from dynamic current clamping and compartmental modeling

Abstract

Gonadotropin releasing-hormone (GnRH) is a small neuropeptide that regulates pituitary release of luteinizing hormone (LH) and follicle-stimulating hormone (FSH). These gonadotropins are essential for the regulation of reproductive function. GnRH release is not continuous, but rather is released in episodic pulses which are essential for reproduction. The identity of the neuronal substrate that results in pulsatile GnRH release, and therefore comprises the GnRH "pulse" generator, is unknown. The intermittent stimuli for GnRH release may arise from input to the GnRH cells and reflect synaptic interactions between GnRH neurons and a secondary network. Alternatively, pulsatile release of GnRH may be a consequence of spontaneous activity of the GnRH neurons themselves. These two hypotheses are not mutually exclusive; the GnRH pulse generator is likely derived from a combination of intrinsic properties and synaptic interactions. I will present evidence from electrophysiological experiments in single GnRH neurons and compartmental models of GnRH neurons that supports a role for excitatory synaptic input as a key regulator of repetitive firing in GnRH neurons.