Crayfish Muscle Receptor Organ: Role in Regulation of Postural Flexion

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Science  11 Feb 1972:
Vol. 175, Issue 4022, pp. 647-650
DOI: 10.1126/science.175.4022.647


Recordings were made from postural-control motor nerves with antagonistic functions in the crayfish abdomen through flexible suction electrodes. During unrestrained flexion of the abdomen, output from the tonic stretch receptor neuron of RM1,(SR1) is sufficient to drive an extensor motor unit in the same segment. However, this intrasegmental "resistance" reflex is normally blocked by an intersegmental reflex in which output from SR1's in caudal segments inhibits SR1 discharge in more anterior segments.