VOCALIZATION ELICITED BY ACTIVATION OF A-DELTA-FIBER AND C-FIBER IN THE RAT

COMPLEX Vocal responses in both the audible and ultrasonic frequency ranges were elicited by a single 2 ms electrical pulse applied to the tail. The first two cries exhibited consistent latencies and durations, were intensity-dependent and were triggered by peripheral fibres with conduction velocities of 7.3 +/- 0.8 and 0.7 +/- 0.1 ms-1, respectively. These behavioural responses are reminiscent of first and second pain triggered by Adelta- and C-peripheral fibres in humans. They were followed by irregular audible cries with a fundamental frequency of 1.5 kHz and '22 kHz ultrasonic calls'.