Peripheral Vasoconstriction in the Rat in Response to Sound: III. Dependence on Pause Characteristics in Continuous Noise

Abstract

The peripheral vascular reaction to sound was studied in the non-anaesthetized rat. Arterial pulsations were recorded by a non-invasive technique from the tail of the animal. The offset of a noise was found to be a weak stimulus for vasoconstriction, eliciting responses in only half of the presentations. A vasoconstriction was, however, regularly elicited by onset of sound after the end of the pause. The vasoconstriction was independent of pause duration in the range 10 ms to 100 s. For shorter pauses the reaction was smaller; the 2 ms pause elicited a vasoconstriction only occasionally. It was especially noted that a 10 ms pause gave a larger response than a 10 ms burst of noise. The results were discussed in relation to decay of sensation and partial masking effects.