Summary
-
1.
Electromyographic recordings were made from a restricted set of flight muscles inLocusta migratoria during flight sequences in intact animals and in animals which had sensory input from the wings and wing-hinges removed. Recordings in intact animals revealed two new features of the flight motor pattern. The first was that the onset of elevator activity followed the onset of depressor activity at an almost constant interval which was independent of wingbeat frequency (Fig. 3), and the second was an almost synchronous activation of the elevator muscles in the two pterothoracic segments (Figs. 5, 6).
-
2.
The most obvious and consistent effects of deafferentation were a decrease in wingbeat frequency and an increase in the magnitude and variability of the interval between the onset of depressor activity and the onset of the following elevator burst. This interval increased from about 20 ms in the intact animals to between 50 and 90 ms in the deafferented animals and became strongly dependent on wingbeat frequency (Fig. 10). The number of spikes/cycle in elevators became more variable and usually increased after deafferentation (Fig. 8). By contrast, deafferentation produced little change in the interval between the termination of the elevator activity and the onset of the following depressor activity (Fig. 10), nor did it produce any major changes in the pattern of discharge in the depressors (Fig. 7).
-
3.
The relative timing of activity in homologous muscles in the two segments became more variable following deafferentation. However, in most deafferented preparations the hindwing depressor activity led the forewing depressor activity by 5 to 10 ms, this being similar to the intersegmental delay observed in intact animals. In all deafferented preparations the elevator activity in the forewings led elevator activity in the hindwings rather than being almost synchronous as in intact animals (Fig. 6).
-
4.
We conclude that deafferentation produces qualitative changes in the flight motor pattern to such an extent that the overall deafferented pattern is distinctly different from the intact motor pattern. In the following paper we show these changes to be due to major changes in the components of synaptic input to elevator motoneurons.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Abbreviations
- EMG :
-
electromyogram
References
Altman JS (1975) Changes in the flight motor pattern during the development of the Australian plague locust,Chortoicetes terminifera. J Comp Physiol 97:127–142
Altman JS, Anselment E, Kutsch W (1978) Postembryonic development of an insect sensory system: ingrowth of axons from the hindwing sense organs inLocusta migratoria. Proc R Soc Lond 202:497–516
Baker PS (1979) The role of forewing muscles in the control of direction in flying locusts. J Comp Physiol 131:59–66
Delcomyn F (1980) Neural basis of rhythmic behavior in animals. Science 210:492–498
Grillner S (1985) Neurobiological bases of rhythmic motor acts in vertebrates. Science 228:143–149
Hedwig B, Pearson KG (1984) Patterns of synaptic input to identified flight motoneurons in the locust. J Comp Physiol A 154:745–760
Kutsch W (1974) The influence of wing sensory organs on the flight motor pattern in maturing adult locusts. J Comp Physiol 88:413–424
Möhl B (1985a) The role of proprioception in locust flight. II. Information signalled by forewing stretch receptors during flight. J Comp Physiol A 156:103–116
Möhl B (1985b) The role of proprioception in locust flight. III. The influence of afferent stimulation of the stretch receptor nerve. J Comp Physiol A 156:281–292
Pearson KG (1985) Are there central pattern generators for walking and flight in insects? In: Barnes WJP, Gladden M (eds) Feedback and motor control in invertebrates and vertebrates. Croom Helm, London, pp 307–316
Pearson KG, Reye DN, Robertson RM (1983) Phase-dependent influence of wing stretch receptors on flight rhythm in the locust. J Neurophysiol 49:1168–1181
Robertson RM, Pearson KG (1982) A preparation for the intracellular analysis of neuronal activity during flight in the locust. J Comp Physiol 146:311–320
Robertson RM, Pearson KG (1983) Interneurons in the flight system of the locust: distribution, connections and resetting properties. J Comp Neurol 215:33–50
Robertson RM, Pearson KG (1985) Neural circuits in the flight system of the locust. J Neurophysiol 53:110–128
Tyrer NM, Altman JS (1974) Motor and sensory flight neurones in a locust demonstrated using cobalt chloride. J Comp Neurol 157:117–138
Waldron I (1967) Mechanisms for the production of the motor output pattern in flying locusts. J Exp Biol 47:201–212
Wendler G (1983) The locust flight system: functional aspects of sensory input and methods of investigation. In: Nachtigall W (ed) Biona Report 2. Gustav Fischer, Stuttgart, pp 113–125
Wilson DM (1961) The central nervous control of flight in a locust. J Exp Biol 38:471–490
Wilson DM, Gettrup E (1963) A stretch reflex controlling wingbeat frequency in grasshoppers. J Exp Biol 40:171–185
Wilson DM, Weis-Fogh T (1962) Patterned activity in co-ordinated motor units, studied in flying locusts. J Exp Biol 39:643–667
Wolf H, Pearson KG (1986) Comparison of motor patterns in the intact and deafferented flight system of the locust. II. Intracellular recordings from flight motoneurons. J Comp Physiol A 160:269–279
Zarnack W, Möhl B (1977) Activity of the direct downstroke flight muscles inLocusta migratoria (L.) during steering behavior in flight. I. Patterns of time shift. J Comp Physiol 118:215–233
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Pearson, K.G., Wolf, H. Comparison of motor patterns in the intact and deafferented flight system of the locust. J. Comp. Physiol. 160, 259–268 (1987). https://doi.org/10.1007/BF00609731
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00609731