H. Rau et al., ACTIVATION OF CAROTID BARORECEPTORS INHIBITS SPINAL REFLEXES IN MAN, Electroencephalography and clinical neurophysiology, 89(5), 1993, pp. 328-334
The present study was designed to investigate the effect of barorecept
ors on a spinal reflex. The Achilles tendon reflex (T reflex), a monos
ynaptic spinal reflex, was chosen as an indicator of descending influe
nces of central activation. The baroreceptors are stretch receptors wh
ich respond to extensions of the arterial wall. Carotid sinus barorece
ptors can be manipulated non-invasively by means of a cuff around the
neck. In this study, the phase-related external suction (PRES) neck cu
ff technique was used. PRES applies short changes in cuff pressure as
a function of heart cycle phase, controlling for non-specific effects
found in other baroreceptor manipulation methods. The T reflex was red
uced when elicited during the highest levels of baroreceptor activatio
n. Reflex amplitude was largest when elicited during the lowest levels
of baroreceptor activation. These results are consistent with previou
s findings that baroreceptor activation reduces CNS excitability.