BIDIRECTIONAL ELECTRICAL COUPLING BETWEEN INSPIRATORY MOTONEURONS IN THE
NEWBORN MOUSE NUCLEUS AMBIGUUS.
Jens C. Rekling, and Jack L. Feldman.
Systems Neurobiology Laboratory, Departments of Physiological Science and
Neurobiology, University of California, Los Angeles, Los Angeles, California
90095-1527.
APStracts 4:209N, 1997.
ABSTRACT
Some spinal and brain stem motoneurons are electrically coupled in the early
postnatal period. To test whether respiratory motoneurons in the brain stem
are electrically coupled we performed single and dual whole-cell patch
recordings from presumptive motoneurons in the nucleus ambiguus in a
rhythmically active brain stem slice from newborn mice. Two of eight (25%)
biocytin-injected neurons showed dye-coupling, and four of eleven (36%) of
intracellularly recorded pairs of neurons showed evidence of bidirectional
electrical coupling. Impulse activity in one cell elicited small spikelets in
the other, and hyperpolarization of one cell led to hyperpolarization of the
other with a coupling ratio ( V2/ V1) of 0.03-0.14. We conclude that
inspiratory ambiguus motoneurons in the newborn mouse brain stem are
bidirectionally electrically coupled, which may serve to transmit or
coordinate signals, chemical or electrical.
Received 15 July 1997; accepted in final form 22 August 1997.
APS Manuscript Number J582-2.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1997 The American Physiological Society.
Published in APStracts on 5 September 1997