Meeting Abstract

P3.108  Wednesday, Jan. 6  Development of a complex motion stimulus to investigate neural substrates of flower tracking in the hawk moth Manduca sexta HEROLD, Paul B*; SPRAYBERRY, Jordanna DH; Muhlenberg College; Muhlenberg College ph235004@muhlenberg.edu

A persistent question in neurobiological research regards how sensory information encoded by the brain produces behavior. The hawk moth Manduca sexta is an excellent model organism for investigating this problem. Hawk moths are rapidly flying nectar feeders that hover in front of flowers. They actively track moving blossoms during feeding bouts, a behavior that is primarily driven by visual cues. Object-sensitive descending neurons (OSDNs) in the cervical connectives of the moth represent highly integrated cells near the sensory-behavioral interface. Recording from OSDNs during stimulation with flower-like motions may elucidate how visual information is processed and encoded as it travels from photoreceptors to thoracic motor centers via the cervical connectives. Flower motions are complex and, as a function of the constraints of the stems, oscillatory in nature. Stimulating OSDNs with equally complex, naturalistic motions allows for the investigation of complex motion encoding that could not be accounted for with a simplistic, unidimensional stimulus. Through the manipulation of random-noise position vectors, I have developed naturalistic flower-like stimuli whose power spectra are consistent with those of hawk moth pollinated flowers. The multiplication of bounding functions with vectors of the power spectra allowed me to filter out the irrelevant frequencies of the noise signals, producing new position vectors that encompass motion dynamics seen in flowers visited by hawk moths. The resulting stimuli, in conjunction with further recordings from OSDNs, will provide new insights into the neural substrates of flower tracking in M. sexta.