Laboratory of Neurophysiology, The Rockefeller University, New York, New
York 10021-6399, USA.
Nausea and vomiting (emesis) occur under a variety of conditions in
response to activation of one or more emetic triggers. The act of vomiting
is coordinated by neuronal circuitry located in the brain stem between the
obex and the retrofacial nucleus, including the region extending from the
nucleus of the solitary tract through the lateral tegmental field of the
reticular formation to the ventrolateral medulla. The area postrema,
medullary midline, and certain higher brain centers are also important for
vomiting. The sensation of nausea is thought to involve the cerebral
cortex. The most effective near-term treatment for combating nausea and
vomiting associated with cyclic vomiting syndrome may come from
experimental drugs (NK-1 receptor antagonists, 5-HT1A receptor agonists)
or P6 acustimulation, which have been shown to combat nausea and vomiting
in response to a broad spectrum of emetic challenges and thus presumably
act on central emetic mechanisms.