Neurophysiological modeling of voiding in the rat; bladder pressure
and post ganglionic bladder nerve activity.
Feber, Joost Le, Els Van Asselt, and Ron Van Mastrigt.
Department of Urology-Urodynamics, Erasmus University Rotterdam,
Rotterdam, The Netherlands
APStracts 3:0256R, 1996.
A model was developed that describes the relations between bladder
pressure and both efferent and afferent nerve activity in post
ganglionic bladder nerves in urethane-anesthetized rats. Nerve
activity was calculated as the 100 msec time integral of the
rectified nerve signal. Afferent and efferent nerve signals were
measured separately by crushing the nerve proximally or distally. A
linear relation was found between bladder pressure and afferent nerve
activity (fit error<7%) and the relation between bladder
pressure and efferent nerve activity was described by a low-pass
filter (fit error<9%). In most experiments combined (efferent
and afferent) nerve activity was measured. Absence of efferent nerve
activity was assumed during the pressure decrease immediately after
voiding. From this episode the afferent nerve activity was estimated
for the entire measurement. Efferent nerve activity was then
estimated assuming linear addition in the bidirectionally conducting
nerves. The model described the measured data very well (fit
error<7%) and the model parameters showed a good reproducibility
in each rat (SD was approximately 30% of the mean).
Received 12 October 1995; accepted in final form 5 June 1996.
APS Manuscript Number R644-5.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 4 July 96