AJP - Heart and Circulatory Physiology, Vol 257, Issue 1 297-H304, Copyright © 1989 by American Physiological Society
Effects of stimulation of fastigial nucleus on cerebral blood flow in cats
J. L. Williams, D. D. Heistad, J. L. Siems and W. T. Talman
Department of Internal Medicine, Veterans Administration Medical Center, University of Iowa College of Medicine, Iowa City 52242.
The goal of this study was to examine effects of electrical stimulation of
the rostral fastigial nucleus on cerebral blood flow. Anesthetized cats
were studied, and arterial pressure and blood gases were maintained at
control levels during fastigial stimulation. In one group, we measured
vessel diameter and velocity of blood flow through a pial artery with a
Doppler probe and calculated blood flow as the product of cross-sectional
area and velocity. Electrical stimulation of the fastigial nucleus produced
a small increase in pial arterial flow of 16 +/- 6% (means +/- SE, P less
than 0.05). Pial vascular resistance increased during moderate hypertension
and decreased during decreases in arterial pressure, which indicates that
cerebral vascular responses were not impaired. In a second group, cerebral
blood flow was measured with microspheres. Blood flow to the pons and
medulla increased 25 +/- 11 and 21 +/- 11%, respectively, during
stimulation of the fastigial nucleus, but blood flow to the cerebral cortex
did not increase significantly. Stimulation produced decreases in flow to
the renal cortex and duodenum of 39 +/- 10 and 39 +/- 15%, respectively,
and flow to the heart increased 48 +/- 22%, which indicates that the
stimulus was efficacious. Thus electrical stimulation of the rostral
fastigial nucleus in cats elicits only a small increase in cerebral blood
flow.
