Studies on cockroach flight: The role of continuous neural activation of non-flight muscles
✍ Scribed by Fourtner, C. R. ;Randall, J. B.
- Publisher
- John Wiley and Sons
- Year
- 1982
- Tongue
- English
- Weight
- 843 KB
- Volume
- 221
- Category
- Article
- ISSN
- 0022-104X
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✦ Synopsis
Abstract
The primary purpose of this study was to identify the muscles active during flight and determine their temporal relationships in the flight‐cycle, thereby laying the foundations for further investigations of the neural control of flight in the cockroach. The wing‐beat frequency of tethered roaches and the frequency of the flight‐cycle in restrained animals was similar, varying between 23 and 30 beats/second. Intracellular recordings of metathoracic and metacoxal muscle were made simultaneously with electromyograms from the elevators of the wing. Muscles 155, 157, 161, 162, 163, 177A, and 174‐6 were active near the onset of elevator activity; muscles 153, 154, 164, 165, 167, 169, and 177C were active approximately 180° out of phase with the elevators. Muscles 177A and 177C, bifunctional in nature, act as antagonists during flight and as synergists to extend the femur. Since the femur is held flexed during flight, the activity of the femoral flexors, 181A‐C and 182C, was determined during flight. 181A and B showed a bimodal phase distribution while 181C and 182C was almost continuously active during flight. Therefore, the flight‐motor‐program reciprocally drives the elevators and depressors and can continuously drive the motor‐neuronal pool operating the femoral flexor. This continuous drive fixes the femur and permits 177A and 177C to act on the thoracic box.