Meeting Abstract
Using a suite of sensory modalities, including vision and mechanoreception, insects process such information control flight. The precision, sensitivity, and rapid processing speeds of mechanoreceptors make them critical components of locomotor control. Further, anatomical, electrophysiological, and behavioral evidence confirms that the wings of the hawkmoth Manduca sexta inform the animal of its body dynamics. However, linking the wings’ bending dynamic to information provided by mechanoreceptors (companiform sensillae) has been unsuccessful with previous intracellular methods. Moreover combined multi-channel extracellular recordings in wing nerves associated with of distributed sensillae did not permit mapping of multiple units to their projections on the wing. However, the strong temperature sensitivity of sensillae allows a novel method to elucidate their regional projections. We used a pulse-width modulated laser to heat and thus selectively deform sensillae on the wing. With simultaneous IR imaging we were able to determine both the location and temperature of the wing region excited by the laser with simultaneous multisite neural recordings. Moreover, using spike-sorting methods, we identified individual units. We showed a consistent increase in spike-rate as the local temperature increased. A maximum increase in spike rate of about 200% was observed for temperatures ranging between 40 – 50 degrees C. Any temperature above 50 degrees Celsius caused a severe decrease in the spike rate, and in some cases death of the cells. Ultimately, in addition to obtaining mechanically induced stimulus excitation of the forewing nerve from individual units, we have demonstrated a novel method to extract location information.
