Proprioceptive Leg Reflexes in Cockroaches

Abstract

Proprioceptive feedback from the moving wings of locusts contains information which could be sufficient for the control of the timing of the wing-muscle contractions. It has been found, however, that at the high frequency of limb movement used in flight this phasic information content is lost in the ganglionic transfer (Wilson & Gettrup, 1963). During rapid running the legs of cockroaches also oscillate at high frequencies, sometimes as rapidly as wing movements of similar-sized animals. It is therefore necessary to know whether the frequency response capabilities of the leg reflexes are similar to or different from those of the wings in order to understand how the legs are coordinated. If the leg reflexes are limited to the same range as that available to the wing reflexes, then coordination of the legs would necessarily depend upon ganglionic phasing mechanisms ; that is, the elementary pattern of leg movements could be due to central nervous control alone, as is true of the locust wing control (Wilson, 1961). However, it can be shown that the phasic leg reflexes are capable of operation at frequencies even greater than those encountered in running. Apparently the significant limitation on rate of leg movement is not nervous but mechanical; that is, due to the maximum rate of contraction of the muscles.