Meeting Abstract

P1.94  Sunday, Jan. 4  Stimulating antennal muscles leads to path changes in a moths flight trajectory TSE, J.C.*; JONG, P.; HINTERWIRTH, A.J.; DANIEL, T.L.; University of Washington; University of Washington; University of Washington; University of Washington jtse106@u.washington.edu

Previous work has shown that mechanoreceptors at the base of the antennae in the crepuscular hawkmoth Manduca sexta are necessary for stable flight control. They mediate flight responses by acting as vibrational gyroscopes, detecting Coriolis forces that appear during body rotations (Sane et al. 2007). We hypothesize that artificially introducing a force that is applied out of the antenna’s vibrational plane should lead to compensatory reactions and therefore to changes in a moth’s flight path. To test this hypothesis, we created small tungsten electrodes that are implanted in the dorso-medial side of the scape, targeting specific extrinsic muscles that lead to antennal retraction (out of the natural vibrational plane). We use a low current 5 V square wave stimulus generated by an Arduino board at 60 Hz with a duty cycle tuned to elicit an antennal retraction without suppressing flight behavior. The stimulus is delivered to the implanted electrodes via a cable of ultrafine stainless steel wire. Thus moths are loosely tethered to the stimulator and permitted to fly. Preliminary experiments show that, in 4 out of 14 animals in which electrode implantation was attempted, stimulation of the left antennal muscles leads to a high probability of left turns immediately following the stimulus. The direction of the elicited response agrees with what is expected if antennae act as gyroscopic sensors. These results provide further evidence that moth antennae are crucial components of a mechanosensor-mediated flight control circuit.