Meeting Abstract
Flying insects use sensory cues from multiple modalities to control their flight. They must acquire, process and respond to perturbations within a few wing beats to ensure stable flight. In the nocturnal hawkmoth Manduca sexta, mechanosensory input from antenna has been shown to be critical for stable flight. These moths also make use of visual inputs to control their flight. The acquisition and processing of visual cues is typically slower than mechanosensory cues in nocturnal insects due to low light levels. How are these multimodal sensory cues integrated by nervous system for rapid flight control? We hypothesized that multiple sensory cues converge to fewer descending interneurons that integrate, process and transmit sensory information to the thoracic ganglion. An alternative (but not mutually exclusive) hypothesis is that such information is transmitted via parallel channels and integrated in the thoracic ganglion. To address these hypotheses, we recorded intracellularly from axons of descending interneurons in the ventral nerve cord of the nocturnal hawkmoth Daphnis nerii. We identified multiple classes of descending interneurons which respond in a tuned manner to both individual and combinatorial mechanical and visual inputs. Together, these data show that descending interneurons integrate multimodal cues, often displaying very specific tuning properties which suggest their specific physiological contribution to flight stabilization.
