Histamine depolarizes rat medial vestibular nucleus neurons recorded intracellularly in vitro

Neurosci Lett. 1990 Feb 16;109(3):287-92. doi: 10.1016/0304-3940(90)90009-x.

Abstract

The effects of histamine (HA) on the resting membrane potential and input resistance of rat medial vestibular nucleus (MVN) neurons were investigated using intracellular recording techniques from a submerged brain slice preparation. The exogenous application of HA predominantly produced a concentration-dependent membrane depolarization and induction of action potential firing. The depolarization exhibited a rapid onset, a slow recovery, and usually occurred in the absence of any apparent change in conductance. These effects of HA could be mimicked by the H2-agonist impromidine and were reversibly blocked by the H2-antagonist cimetidine. Tetrodotoxin (TTX) or low calcium/high magnesium-containing media failed to block completely the HA-induced depolarization supporting a direct postsynaptic receptor mediated action of HA. The diminished HA-induced depolarization observed following pretreatment with TTX cannot exclude an additional presynaptic action by HA. The present findings reveal that HA exerts a novel direct excitation of rat MVN neurons through an H2-receptor.

Publication types

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

MeSH terms

  • Action Potentials / drug effects
  • Animals
  • Cimetidine
  • Guanidines / pharmacology
  • Histamine / pharmacology*
  • Imidazoles / pharmacology
  • Impromidine
  • In Vitro Techniques
  • Male
  • Rats
  • Rats, Inbred Strains
  • Receptors, Histamine / drug effects
  • Receptors, Histamine / physiology*
  • Vestibular Nerve / drug effects
  • Vestibular Nerve / physiology*

Substances

  • Guanidines
  • Imidazoles
  • Receptors, Histamine
  • Cimetidine
  • Histamine
  • Impromidine