5-HT3 receptor-dependent modulation of respiratory burst frequency, regularity, and episodicity in isolated adult turtle brainstems

Michelle E. Bartman, Julia E R Wilkerson, Stephen M. Johnson

Research output: Contribution to journalArticle

6 Scopus citations


To determine the role of central serotonin 5-HT3 receptors in respiratory motor control, respiratory motor bursts were recorded from hypoglossal (XII) nerve rootlets on isolated adult turtle brainstems during bath-application of 5-HT3 receptor agonists and antagonists. mCPBG and PBG (5-HT3 receptor agonists) acutely increased XII burst frequency and regularity, and decreased bursts/episode. Tropisetron and MDL72222 (5-HT3 antagonists) increased bursts/episode, suggesting endogenous 5-HT3 receptor activation modulates burst timing in vitro. Tropisetron blocked all mCPBG effects, and the PBG-induced reduction in bursts/episode. Tropisetron application following mCPBG application did not reverse the long-lasting (2 h) mCPBG-induced decrease in bursts/episode. We conclude that endogenous 5-HT3 receptor activation regulates respiratory frequency, regularity, and episodicity in turtles and may induce a form of respiratory plasticity with the long-lasting changes in respiratory regularity.

Original languageEnglish (US)
Pages (from-to)42-52
Number of pages11
JournalRespiratory Physiology and Neurobiology
Issue number1-2
Publication statusPublished - Jun 30 2010



  • 5-HT receptors
  • Chelonian
  • Episodic breathing
  • Frequency
  • Plasticity
  • Regularity
  • Reptile
  • Respiratory motor control
  • Serotonin

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine
  • Neuroscience(all)
  • Medicine(all)

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