Department of Pharmacology and Toxicology, Michigan State University, East Lansing, Michigan 48824, USA
Address for communication: Susan M. Barman, Department of Pharmacology and Toxicology, Michigan State University, East Lansing, MI 48824. Voice: 517-432-3154; fax: 517-353-8915.
barman{at}msu.edu
Data from experiments with single neuron recordings as well
as central microinjections of
N-methyl-d-aspartate (NMDA) and
non-NMDA excitatory amino receptor antagonists that have led
to a model of central sympathetic pathways that includes synaptic
relays in the medullary lateral tegmental field (LTF) of the
cat are summarized. Evidence is presented that (1) the LTF contains
a population of tonically active sympathoexcitatory neurons
that drive rostral ventrolateral medullary neurons, (2) blockade
of non-NMDA receptors in the LTF significantly reduces basal
levels of sympathetic nerve discharge (SND) and mean arterial
pressure in baroreceptor-denervated cats, and (3) blockade of
NMDA-mediated neurotransmission in the LTF prevents baroreceptor
reflex control of SND. Thus, LTF neurons play an important role
in the generation and baroreceptor reflex control of SND in
the cat.
