Serotonin inhibits calcium-activated K+ current in rat taste receptor cells

Neuroreport. 1997 Oct 20;8(15):3257-61. doi: 10.1097/00001756-199710200-00014.

Abstract

Little is definitively known of the identity or actions of neurotransmitters utilized within mammalian taste buds. Serotonin has been immunocytochemically localized to taste cells of several species but its physiological actions are unknown. Using whole-cell patch clamp recordings on dissociated posterior rat taste cells, data are presented to suggest that exogenously applied serotonin inhibits a calcium-activated potassium current by up to 50%. This current, best visualized at depolarized holding potentials, is both apamin- and charybdotoxin-sensitive. Approximately 60% of the tested taste cells were serotonin sensitive. This inhibition was mimicked by N-(3-trifluoromethylphenyl)piperazine (TFMPP), a general serotonin receptor agonist, by 8-hydroxy-dipropylaminotetralin (8-OH-DPAT), a selective 5-HT1A receptor agonist, but not by phenylbiguanide, a 5-HT3 receptor agonist. These are the first data to establish a physiological effect of serotonin on mammalian taste cells.

Publication types

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

MeSH terms

  • 8-Hydroxy-2-(di-n-propylamino)tetralin / pharmacology
  • Animals
  • Calcium / physiology*
  • Electrophysiology
  • In Vitro Techniques
  • Membrane Potentials / drug effects
  • Membrane Potentials / physiology
  • Patch-Clamp Techniques
  • Piperazines / pharmacology
  • Potassium Channel Blockers*
  • Potassium Channels / drug effects
  • Rats
  • Serotonin / pharmacology*
  • Serotonin Receptor Agonists / pharmacology
  • Taste / drug effects
  • Taste / physiology*
  • Taste Buds / drug effects
  • Taste Buds / physiology*

Substances

  • Piperazines
  • Potassium Channel Blockers
  • Potassium Channels
  • Serotonin Receptor Agonists
  • 1-(3-trifluoromethylphenyl)piperazine
  • Serotonin
  • 8-Hydroxy-2-(di-n-propylamino)tetralin
  • Calcium