Serotonin enhances excitability in neostriatal neurons by reducing voltage-dependent potassium currents

Alessandro Stefani, D. James Surmeier, S. T. Kitai

Research output: Contribution to journalArticlepeer-review


The physiological effects of serotonin (5-HT) on rat neostriatal neurons were investigated using current-clamp techniques in neostriatal slices and voltage-clamp techniques in acutely dissociated adult neostriatal neurons. In most neurons (35/51), bath-applied 5-HT (10-60 gmM) decreased the first spike latency and increased the evoked firing frequency. Membrane input resistance was also increased in most neurons (35/35) but could not explain the enhanced responsiveness. Tetrodotoxin, at concentrations sufficient to block spike production, did not block the ability of 5-HT to enhance the slow ramp-like voltage trajectory produced by depolarizing current injection. The role of potassium currents in the 5-HT effect was examined using whole cell voltage-clamp; in 6 of 9 neurons, 5-HT reversibly decreased inactivating potassium currents activated by depolarization. These experiments suggest that 5-HT's effect on the ramp trajectory may be mediated by a reduction of potassium currents activated by sub-threshold depolarization.

Original languageEnglish
Pages (from-to)354-357
Number of pages4
JournalBrain Research
Issue number1-2
Publication statusPublished - Oct 8 1990


  • Modulation
  • Neostriatum
  • Potassium current
  • Serotonin
  • Voltage-clamp

ASJC Scopus subject areas

  • Developmental Biology
  • Molecular Biology
  • Clinical Neurology
  • Neuroscience(all)

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