Department of Physiology, Wayne State University School of Medicine, 540 East Canfield Avenue, Detroit, Michigan 48201, USA
Address for correspondence: Jeffrey T. Potts, Ph.D., Department of Physiology, Wayne State University School of Medicine, 540 E. Canfield Ave., Detroit, MI 48201. Voice: 313-577-9295; fax: 313-577-5494.
jtpotts{at}med.wayne.edu
Since NTS neurons receive synaptic input from many sensory modalities,
it is crucial to understand the neuronal mechanisms involved
in synaptic processing. We have proposed that GABA-containing
neurons in the NTS are the primary target for somatic afferent
fibers activated by skeletal muscle contraction. In our model,
local inhibition of baroreceptor signaling is necessary to counteract
the increase in baroreceptor input such that NTS output is normalized
and baroreflex sensitivity is maintained during exercise. This
GABAergic mechanism, in conjunction with sympathoexcitation
evoked by somatic afferents, preserves reflex sensitivity and
resets the baroreflex, respectively. Unfortunately, there is
insufficient data to date to support or refute the proposed
role for GABA on baroreflex function during exercise. However,
we feel that this model will be useful in formulating future
experiments to explore these synaptic interactions.
