Chemosensitive serotonergic neurons are closely associated with large medullary arteries

Nat Neurosci. 2002 May;5(5):401-2. doi: 10.1038/nn848.

Abstract

We have previously shown that serotonergic neurons of the medulla are strongly stimulated by an increase in CO(2), suggesting that they are central respiratory chemoreceptors. Here we used confocal imaging and electron microscopy to show that neurons immunoreactive for tryptophan hydroxylase (TpOH) are tightly apposed to large arteries in the rat medulla. We used patch-clamp recordings from brain slices to confirm that neurons with this anatomical specialization are chemosensitive. Serotonergic neurons are ideally situated for sensing arterial blood CO(2), and may help maintain pH homeostasis via wide-ranging effects on brain function. The results reported here support a recent proposal that sudden infant death syndrome (SIDS) results from a developmental abnormality of medullary serotonergic neurons.

Publication types

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

MeSH terms

  • Animals
  • Arteries / innervation*
  • Arteries / ultrastructure
  • Chemoreceptor Cells / cytology
  • Chemoreceptor Cells / metabolism*
  • Medulla Oblongata / blood supply*
  • Medulla Oblongata / cytology
  • Medulla Oblongata / physiology
  • Neurons / metabolism
  • Neurons / physiology*
  • Neurons / ultrastructure
  • Rats
  • Serotonin / metabolism*
  • Tryptophan Hydroxylase / biosynthesis

Substances

  • Serotonin
  • Tryptophan Hydroxylase