CUTANEOUS VASOCONSTRICTION WITH ALERTING STIMULI IN RABBITS REFLECTS A PATTERNED REDISTRIBUTION OF CARDIAC OUTPUT

1. In conscious rabbits, when alerting stimuli elicit vasoconstriction in the ear vascular bed, there is little or no associated change in cardiac output (CO), as measured by chronically implanted Doppler ultrasonic probes. 2. Local anaesthetic injected around the base of the ear substantially diminished the degree of the vasoconstriction elicited during responses. 3. Our results emphasize that selective cutaneous vasoconstriction, an integral part of the response to alerting stimuli in conscious animals, is part of a patterned redistribution of the CO, organized by the brain.