Existence of the acoustic cricothyroid response in the rat

A recent investigation by P. H‐S. Jen et al. [J. Acoust. Soc. Am. 57, S42 (A) (1975)] has shown that during acoustic stimulation the cricothyroid musclc (CTM) responds in echolocating bats. Previous studies have shown that the rat emits ultrasonic cries which can be used to echolocate. Our study attempts to determine the existence of the acoustic CTM response in this species. Electromyography of the CTM was obtained in ten rats. Rats were stimulated with pure tones between 5 and 60 kHz. During acoustic stimulation the rate of the action potential response was obtained using varying intensities and frequencies. Interspike interval histograms were also obtained during spontaneous activity from the CTM. Latencies from the CTM response were found to be within the range of 8 to 30 msec. Data are presented which support the acoustic CTM response in the rat.