Presynaptic inhibition of sensory neurons during kicking movements in the
locust.
Hedwig, Berthold and Malcolm Burrows.
Department of Zoology, University of Cambridge, Cambridge CB2 3EJ,
England.
APStracts 2:0297N, 1995.
SUMMARY AND CONCLUSIONS
Locusts use a distinctive motor pattern to extend the tibia of a hind leg
rapidly in a defensive kick, or to extend the tibiae of both hind legs in a
jump. The force for the movement is generated by an almost isometric co-
contraction of the extensor and flexor tibiae muscles followed by a sudden
release of the stored energy when the flexor motor neurons are inhibited. A
proprioceptor (the femoral chordotonal organ) spans the femoro- tibial joint
and at least 50 of its sensory neurons each signal particular features of its
movements. Intracellular recordings from these neurons close to their
terminals in the central nervous system show that their spikes during kicking
are superimposed on a depolarising synaptic input generated near their output
terminals. The depolarisation is linked to the time in the motor pattern when
the sensory neurons spike.
Received 14 June 1995; accepted in final form 17 October 1995.
APS Manuscript Number J379-5.
Article publication pending J. Neurophysiol.
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 6 November 95