Effect of spinal cord temperature on carotid blood flow in the Pekin duck.

Spinal cord heating in white Pekin ducks increases breathing rate and carotid blood flow. During naturally induced panting, the reverse effect was achieved by spinal cooling. An increased beak and expired air temperature during spinal heating suggest an importance of the increased carotid blood flow in maximizing heat dissipation during polypnoea. The results indicate that both the polypneic response and the increase in carotid blood flow are dependent on the same sensory input, namely the temperature of the spinal cord.