5-Hydroxytryptamine modulates spike frequency regulation in reticulospinal neurons involved in the control of locomotion in lamprey

Neurosci Lett. 1992 Jan 6;134(2):279-83. doi: 10.1016/0304-3940(92)90535-f.

Abstract

To investigate the effects of 5-hydroxytryptamine (5-HT) on reticulospinal neurons involved in the initiation and control of locomotion in lamprey, 5-HT (10 mM) was locally pressure ejected on the dorsal surface of the brainstem during intracellular recordings from identified reticulospinal neurons in the in vitro brainstem-spinal cord preparation. 5-HT induced a reduction of the late afterhyperpolarization (AHP) following the spike due to a reduction of a Ca(2+)-activated K+ current. In addition, 5-HT caused a resting membrane hyperpolarization in a proportion of these cells. Due to the 5-HT induced reduction of the AHP, reticulospinal cells, including those that became hyperpolarized by an application of 5-HT, discharged at a higher rate after 5-HT as a response to the same excitatory drive.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Evoked Potentials / drug effects
  • In Vitro Techniques
  • Lampreys
  • Larva
  • Membrane Potentials / drug effects
  • Motor Activity / drug effects
  • Motor Activity / physiology*
  • N-Methylaspartate / pharmacology
  • Neurons / drug effects
  • Neurons / physiology*
  • Reticular Formation / drug effects
  • Reticular Formation / physiology*
  • Rhombencephalon / drug effects
  • Rhombencephalon / physiology*
  • Spinal Cord / drug effects
  • Spinal Cord / physiology*
  • Tetraethylammonium
  • Tetraethylammonium Compounds / pharmacology
  • Tetrodotoxin / pharmacology

Substances

  • Tetraethylammonium Compounds
  • Tetrodotoxin
  • N-Methylaspartate
  • Tetraethylammonium