Synchronized Network Oscillations in Rat Tuberoinfundibular Dopamine Neurons: Switch to Tonic Discharge by Thyrotropin-Releasing Hormone

David J Lyons, Emilia Horjales-Araujo, Christian Broberger

Research output: Contribution to journalArticlepeer-review

Abstract

The pituitary hormone, prolactin, triggers lactation in nursing mothers. Under nonlactating conditions, prolactin secretion is suppressed by powerful inhibition from hypothalamic tuberoinfundibular dopamine (TIDA) neurons. Although firing pattern has been suggested as integral to neuroendocrine control, the electrical behavior of TIDA cells remains unknown. We demonstrate that rat TIDA neurons discharge rhythmically in a robust 0.05 Hz oscillation. The oscillation is phase locked between neurons, and while it persists during chemical synaptic transmission blockade, it is abolished by gap junction antagonists. Thyrotropin-releasing hormone (TRH) potently stimulates prolactin release, an effect assumed to take place in the pituitary. In TIDA cells, TRH caused a transition from phasic to tonic firing through combined pre- and postsynaptic effects. These findings suggest a model for prolactin regulation where a TIDA network switch from oscillations to sustained discharge converts dopamine from an antagonist at high concentrations to a functional agonist as dopamine output from the network decreases.

Original languageEnglish
Pages (from-to)217-229
Number of pages13
JournalNeuron
Volume65
Issue number2
DOIs
Publication statusPublished - 28 Jan 2010

Keywords

  • Animals
  • Arcuate Nucleus of Hypothalamus/physiology
  • Biological Clocks/physiology
  • Dopamine/physiology
  • Male
  • Nerve Net/physiology
  • Neurons/physiology
  • Rats
  • Rats, Sprague-Dawley
  • Thyrotropin-Releasing Hormone/physiology

Fingerprint

Dive into the research topics of 'Synchronized Network Oscillations in Rat Tuberoinfundibular Dopamine Neurons: Switch to Tonic Discharge by Thyrotropin-Releasing Hormone'. Together they form a unique fingerprint.

Cite this