Cardiopulmonary baroreceptors affect reflexive startle eye blink.
Baroafferent signals originating from the 'high pressure' arterial vascular system are known to impact reflexive startle eye blink responding. However, it is not known whether baroafferent feedback of the 'low pressure' cardiopulmonary system loading status exerts a similar effect. Lower Body Negative Pressure (LBNP) at gradients of 0, -10, -20, and -30mm Hg was applied to unload cardiopulmonary baroreceptors. Acoustic startle noise bursts were delivered 230 and 530ms after spontaneous R-waves, when arterial baroreceptors are either loaded or unloaded. Eye blink responses were measured by EMG, and psychomotor reaction time by button pushes to startle stimuli. The new finding of this study was that unloading of cardiopulmonary baroreceptors increases startle eye blink responsiveness. Furthermore, we replicated the effect of relative loading/unloading of arterial baroreceptors on startle eye blink responsiveness. Effects of either arterial or cardiopulmonary baroreceptor manipulations were not present for psychomotor reaction times. These results demonstrate that the loading status of cardiopulmonary baroreceptors has an impact on brainstem-based CNS processes.
Division of Clinical Physiology, Institute of Psychobiology, University of Trier, D-54290 Trier, Germany. richters@uni-trier.de
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Richter
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Schulz
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Port
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Blumenthal
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Schächinger
D000161:Acoustic Stimulation / Q000009:adverse effects; D000328:Adult; D000704:Analysis of Variance; D001767:Blinking / Q000502:physiology*; D001794:Blood Pressure / Q000502:physiology; D002339:Carotid Arteries / Q000502:physiology*; D004562:Electrocardiography / Q000379:methods; D004576:Electromyography / Q000379:methods; D006801:Humans; D008150:Lower Body Negative Pressure / Q000379:methods*; D008297:Male; D011311:Pressoreceptors / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology; D011601:Psychophysics; D011651:Pulmonary Artery / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D013216:Reflex, Startle / Q000502:physiology*; D055815:Young Adult