Serotonergic inhibition of phrenic motoneuron activity: an in vitro study in neonatal rat

Neurosci Lett. 1997 Jul 11;230(1):29-32. doi: 10.1016/s0304-3940(97)00469-2.

Abstract

In vitro experiments were conducted on neonatal rat brainstem-spinal cord preparations to test the hypothesis of an inhibitory modulation of phrenic activity by serotonin (5-HT) via non-5-HT2A receptors [Lindsay, A.D. and Feldman, J.L., Modulation of respiratory activity of neonatal rat phrenic motoneurones by serotonin, J. Physiol., 461 (1993) 213-233]. The changes induced by 5-HT and related agents on phrenic root discharges and membrane currents in identified phrenic motoneurons were analysed after blockade of spinal 5-HT2A receptors. Spinal application of 5-HT1B (but not 5-HT1A) receptor agonists depressed the phrenic activity and the effect was prevented by pretreatment with 5-HT1B (but not 5-HT1A, 5-HT2A and 5-HT3) receptor antagonists. Results from phrenic motoneuron whole cell recordings do not reject a presynaptic location of the 5-HT receptors responsible for this depression.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Action Potentials / physiology
  • Animals
  • Animals, Newborn
  • Brain Stem / physiology*
  • In Vitro Techniques
  • Indoles / pharmacology
  • Motor Neurons / drug effects
  • Motor Neurons / physiology*
  • Phrenic Nerve / physiology*
  • Rats
  • Receptors, Serotonin / physiology
  • Serotonin / pharmacology*
  • Serotonin Receptor Agonists / pharmacology
  • Spinal Cord / physiology*
  • Synaptic Transmission / drug effects
  • Synaptic Transmission / physiology

Substances

  • Indoles
  • Receptors, Serotonin
  • Serotonin Receptor Agonists
  • 5-methoxy 3-(1,2,3,6-tetrahydro-4-pyridinyl)1H indole
  • Serotonin