Properties of postganglionic sympathetic fibers isolated from the
right recurrent laryngeal nerve.
Bakowiec, Agnieszka, and Pawe Szulczyk.
Katedra i Zakad Fizjologii Czowieka, Akademii Medycznej w
Warszawie, Krakowskie Przedmiecie 26/28, 00 325 Warszawa, POLAND
APStracts 2:0134A, 1995.
The pattern of response of 45 single postganglionic sympathetic axons
dissected from the right recurrent laryngeal nerve was examined in
chloralose-anesthetized cats. Both vago-aortic nerves were cut and
both sinus nerves were left intact. Each neuron, based on the
presence of cardiac and respiratory rhythmicities in its resting
activity, and reaction to systemic hypoxia (10% O2 in N2 for 2 min.),
was classified into one of three classes. Class I neurons (n=29, 64%)
were activated during systemic hypoxia and had a pronounced cardiac
and inspiration-related rhythmicity in their resting activity. Class
II neurons (n=12, 27%) were inhibited during systemic hypoxia and
their cardiac and respiratory rhythmicities were either negligible or
totally absent. Class III neurons (n=4, 9%), similarly to class I,
had a pronounced cardiac and inspiratory rhythmicity but were not
affected by systemic hypoxia. The systemic hypoxia was always
accompanied by an increase in blood pressure. We conclude that class
I, and possibly class III neurons innervate the arteries of upper
airways. We also discuss the possibility that class II neurons are
the ones responsible for regulating the smooth muscles of upper
airways.
Received 27 December 1994; accepted in final form 16 March 1995.
APS Manuscript Number A1336-4.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 4 April 1995.