Inhibition of an abdominal proprioceptive reflex in crayfish

Summary Stimulation of the tonic muscle receptor organs inProcambarus clarkii results in reflex activation of the superficial extensors. This pathway is inhibited by activity in the lateral giant fibers and both medial giants. A labile synapse in the same pathway works synergistically with the giant fiber-mediated inhibition to prevent maladaptive activation of the superficial extensors during escape behavior. Evidence did not support the notion of giant fiber-mediated peripheral inhibition (via the accessory nerve) of MRO activity.This work was supported by NIH grant NS 02944 (to D. Kennedy). I would like to thank Drs. Kennedy, Wine, and the members of the Kennedy laboratory for their help and support.