QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by WALDRON, I. Search for Related Content PubMed PubMed Citation Articles by WALDRON, I.

Journal of Experimental Biology 47,213-228 (1967)
Published by Company of Biologists 1967

Neural Mechanism by Which Controlling Inputs Influence Motor Output in the Flying Locust

INGRID WALDRON ¹

¹ Department of Zoology, University of California, Berkeley; Physiological Laboratory, Cambridge, England

1. The central nervous system of the flying locust generates a pattern of alternating bursts of impulses in the elevator and depressor motor neurons (Wilson, 1961). The mechanism by which controlling inputs modify this output pattern is analysed in this paper.

2. During roll turns and other flight manoeuvres the average number of impulses per burst (average burst length) changes in certain motor neurons. Changes in average burst length develop slowly, over tens of wingbeat cycles, even in response to the abrupt changes in input which result from electrical stimulation of sensory nerves.

3. In addition to the slow changes in average burst length which are elicited by controlling inputs, more rapid changes in burst length sometimes occur. During this rapid variation a longer burst is usually followed by a shorter burst, probably because the motor neuron is less excitable after a longer burst of activity. Burst length varies independently in different motor neurons. Both findings suggest that much of the rapid variation in burst length is due to changes occurring within the individual motor neurons, and is not a response to rapid changes in controlling inputs.

4. Under all conditions, changes in the number of impulses per burst are correlated with small changes in the relative timing of the burst; the longer bursts produced by a motor neuron begin slightly earlier in the wingbeat cycle. This implies that the factors which cause variation in the length of the bursts are also responsible for producing the variation in the timing of the bursts.

5. All of the observations can be explained on one assumption: that the only effect of controlling inputs is to cause slow changes in the ‘average excitation’ of individual motor neurons. Thus sensory and central control of the flight pattern generating system appears to be slow control over the average performance, rather than fast control over performance in a particular cycle.

This article has been cited by other articles:

				J. M. Camhi and M. Hinkle Attentiveness to Sensory Stimuli: Central Control in Locusts Science, February 4, 1972; 175(4021): 550 - 553. [Abstract] [PDF]