Meeting Abstract

P2.157  Tuesday, Jan. 5  Radio controlled stimulation of abdominal flexion in Manduca sexta affects the flight path. ALDWORTH, Z.; LOCKEY, J.*; OTTEN, D.; LANG, J.; VOLDMAN, J.; DANIEL, T.; Univ. Washington, Seattle; Univ. Washington, Seattle; Mass. Inst. Technology, Boston; Mass. Inst. Technology, Boston; Mass. Inst. Technology, Boston; Univ. Washington, Seattle danielt@uw.edu

Control of flight in insects involves multiple actuators including wings, legs and the abdomen. While wing motions are thought to dominate flight forces, relatively little attention has been given to the role of abdominal motions in flight control – either as a rudder or way of shifting the center of mass relative to the center of lift. To understand the potential role of abdominal flexion in flight control, prior studies have focused on either tethered preparations or on observations of natural abdominal motions during flight maneuvers. Recent advances in radio technology, along with the development of stimulation methods for the ventral nerve cord of Manduca sexta permit remote control of abdominal motions and, thus, provide direct tests of the potential role of the abdominal motions determining flight trajectories. We used a microPIC controller combined with an ultra-miniature radio receiver mounted on the animal to deliver pulse-width modulated, bipolar stimulation (100 Hz, duty cycle 50%, ±2.5 – 3V) to freely flying moths. We stimulated the ventral nerve cord in three separate animals, placing tungsten electrodes in the connective between the last thoracic ganglion and the first abdominal ganglion in each case. All three animals showed a pitch upwards in response to that stimulation and resulting abdominal flexion. These results demonstrate that we can elicit abdominal movement remotely in freely-flying animals, and further indicate that such abdominal flexion can indeed affect the flight path.