required reading:
Johnston RM, Levine RB (1996). Locomotory behavior in the hawkmoth Manduca sexta: kinematic and electromyographic analyses of the thoracic legs in larvae and adults. J exp Biol 199:759-774.
pdf file

questions:

1. What is the relationship of central pattern generation and locomotion? Since locomotion is a motor activity, can we forget about sensory input?
2. What is the main goal of this paper? Why was Manduca studied?
3. What is the definition of "cycle" in this paper?
4. Collect all the terms related to lifting and lowering a leg. How is "leg lifted" depicted in the graphs?
5. Describe crawling behavior and its relationship to EMG activity (Figure 3D).
6. Why did the authors do a regression analysis and what did they learn from it? (Figure 4)
7. Compare and contrast stepping patterns and crawling patterns. What were the patterns observed? (Figure 5)
8. Compare and contrast EMG activity during stepping and crawling? (Figure 6)
9. Why study airstepping? What did the authors find?
10. Compare and contrast the data from figures 7 and 9.
11. Describe central pattern generation in the larva and the adult. What is the significance of this paper in terms of understanding neural circuitry >underlying locomotion?

pdf-file of power point presentation (about 2.8 MB)

background reading:

Rose, U and Levine, RB (2000) Comparison of identified leg motoneuron structure and function in larval and adult Manduca sexta. J. Comp. Physiol. 186:327-336. pdf-file

Belanger JH, Trimmer BA (2000) Combined kinematic and electromyographic analyses of proleg function during crawling by the caterpillar Manduca sexta. J comp Physiol A 186:1031-1039. pdf-file

Johnston RM, Consoulas C, Pflüger HJ, Levine RB (1999) Patterned activation of unpaired median neurons during fictive crawling in Manduca sexta larvae. J exp Biol 202:103-113. pdf-file

A lot of walking studies have been done on stick insects and cockroaches: here some review papers for the student striving to get some knowledge in this field:
Bässler, U., Büschges, A. (1998) Pattern generation for walking movements of stick insects - multisensory control of a locomotor program. Brain Research Reviews 27/1: 65-88 pdf-file
Büschges, A., El Manira A. (1998) Sensory pathways and their modulation in the control of locomotion. Curr. Opin. Neurobiol. 8, 733-739 pdf-file
Delcomyn, F. 1999. Walking robots and the central and peripheral control of locomotion in insects. Auton. Rob. 7, 259-270. pdf-file

Links:
Publications about motor system in Manduca from the Levine Lab
Model systems in neuroethology: walking cockroach
Neural control of posture and locomotion (Büschges-Lab)
Biological cybernetics research Bielefeld (walking) (Cruse-Lab)
Fred Delcomyn's Web Site
UIUC Hexapod Project
Roy Ritzman's Web Site