Meeting Abstract
Flying insects rely on multi-modal, tightly coordinated sensorimotor systems to accomplish complex flight trajectories. To execute adaptive, compensatory maneuvers, insects acquire and process feedback from proprioceptive input from a variety of structures including the head, antennae, and wings. Recently, attention has focused on the flight control role played by the abdomen, commonly the structure with the greatest mass in many flying insects. Interestingly, little is known of the proprioceptive feedback provided by any mechanosensory structures associated with the abdomen position. We asked whether information from abdominal mechanosensors can be detected in ventral nerve cord and, if so, what are the temporal characateristics of neuronal responses to mechanical stimulation of the abdomen. Using Manduca sexta to examine abdominal mechanosensing we first identified a suite of hairplates located on the dorsal aspect of the abdomen that potentially detect dorsal abdominal extension. We then used multisite extracellular recording methods to measure neural responses in the ventral nerve cord for a preparation consisting of a thorax and abdomen. The abdomen was subject to a step-wise rapid dorsoflexion via a high speed servomotor. We identified neural responses in the form of rapid spiking that occurred within 50 ms of the onset of step stimulus. Additionally, these units show very rapid adaption to the stimulus, ceasing firing within approximately 250 ms. These data suggest that, as expected, there is fast proprioceptive input available to the flying animal. Moreover, that rapid adaption to the stimulus suggests that this input could provide rate detection for abdominal motions.
