Neurons in the dorsal motor nucleus of the vagus may integrate vagal and
spinal sensory information from the gastrointestinal tract.
Renehan, William E., Xueguo Zhang, William H. Beierwaltes, and Ronald Fogel.
Laboratory of Gastrointestinal, Gustatory and Somatic Sensation and
Division of Hypertension Research, Henry Ford Health Sciences Center, Case
Western Reserve University, Detroit, MI 48202
APStracts 2:0008G, 1995.
Previous investigations have provided evidence that the activity of
parasympathetic efferent neurons in the dorsal motor nucleus of the vagus
(DMNV) may be influenced by either vagal afferent or spinal input. Many
questions remain, however, regarding the nature of this input and its
integration by the brainstem. The present study was designed to examine one
important aspect of this issue--the potential contribution of the spinal
input to the brainstem in the generation of the response properties of
intestine-sensitive neurons in the DMNV. Using intracellular recording and
labeling techniques in adult rats, we found that ascending spinal pathways
were capable of conveying both low- and high threshold visceral information
to the DMNV. We also determined that the neurons in the nucleus of the
solitary tract (NST) failed to respond to intestinal distention if the vagal
afferents to the brainstem had been severed, suggesting that the spinal
projections terminate directly on the DMNV neurons. These data lend support
to the emerging hypothesis that the spinal afferents that accompany the
abdominal splanchnics are capable of responding to both innocuous and noxious
stimuli. The results also suggest that the neurons in the DMNV play a larger
role in the integration of visceral sensory information than was previously
realized.
Received 8 August 1994; accepted in final form 10 January 1995.
APS Manuscript Number G295-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 23 February 1995.