Selective mechanical stimulation of an identified proprioceptor in freely moving locusts: role of resistance reflexes in active posture.
Direct mechanical stimulation of an identified proprioceptive sense organ, the femoral chordotonal organ of the locust hindleg, has been applied in freely moving animals to evaluate its function in maintenance of posture. A piezo-electric crystal mounted on the leg produced displacements of the main ligament of the organ mimicking 10-15 degree changes in joint angle. These stimuli produced consistent responses that (1) occurred as resistance reflexes to oppose the apparent joint movement and (2) demonstrated strong, tonic coupling of motoneuron activity to afferent input. These experiments have, therefore, directly demonstrated that the chordotonal organ functions in posture to aid in load compensation and to set the level of tonic motoneuron activity.
D000818:Animals; D006110:Grasshoppers / Q000502:physiology*; D008297:Male; D008465:Mechanoreceptors / Q000502:physiology*; D009043:Motor Activity / Q000502:physiology*; D009046:Motor Neurons / Q000502:physiology; D011187:Posture; D011434:Proprioception; D012018:Reflex / Q000502:physiology*