Deciphering the Role of a Coleopteran Steering Muscle via Free Flight Stimulation

• Main Authors: Sato, Hirotaka, Vo Doan, Tat Thang, Kolev, Svetoslav, Huynh, Ngoc Anh, Zhang, Chao, Massey, Travis L., van Kleef, Joshua, Ikeda, Kazuo, Abbeel, Pieter, Maharbiz, Michel M.
• Other Authors: School of Electrical and Electronic Engineering
• Format: Article
• Language: English
• Published: 2016
• Subjects: biomechanics; Electric Stimulation
• Online Access: https://hdl.handle.net/10356/81941; http://hdl.handle.net/10220/41046
• Institution: Nanyang Technological University

Testing hypotheses of neuromuscular function during locomotion ideally requires the ability to record cellular responses and to stimulate the cells being investigated to observe downstream behaviors [ 1 ]. The inability to stimulate in free flight has been a long-standing hurdle for insect flight studies. The miniaturization of computation and communication technologies has delivered ultra-small, radio-enabled neuromuscular recorders and stimulators for untethered insects [ 2–8 ]. Published stimulation targets include the areas in brain potentially responsible for pattern generation in locomotion [ 5 ], the nerve chord for abdominal flexion [ 9 ], antennal muscles [ 2, 10 ], and the flight muscles (or their excitatory junctions) [ 7, 11–13 ]. However, neither fine nor graded control of turning has been demonstrated in free flight, and responses to the stimulation vary widely [ 2, 5, 7, 9 ]. Technological limitations have precluded hypotheses of function validation requiring exogenous stimulation during flight. We investigated the role of a muscle involved in wing articulation during flight in a coleopteran. We set out to identify muscles whose stimulation produced a graded turning in free flight, a feat that would enable fine steering control not previously demonstrated. We anticipated that gradation might arise either as a function of the phase of muscle firing relative to the wing stroke (as in the classic fly b1 muscle [ 14, 15 ] or the dorsal longitudinal and ventral muscles of moth [ 16 ]), or due to regulated tonic control, in which phase-independent summation of twitch responses produces varying amounts of force delivered to the wing linkages [ 15, 17, 18 ].