Chiappe ME, Seelig JD, Reiser MB, Jayaraman V
Walking Modulates Speed Sensitivity in Drosophila Motion Vision.
Curr Biol. 2010 Aug 24;20(16):1470-1475
Authors: Chiappe ME, Seelig JD, Reiser MB, Jayaraman V
Changes in behavioral state modify neural activity in many systems [1-5]. In some vertebrates such modulation has been observed and interpreted in the context of attention  and sensorimotor coordinate transformations . Here we report state-dependent activity modulations during walking in a visual-motor pathway of Drosophila. We used two-photon imaging to monitor intracellular calcium activity in motion-sensitive lobula plate tangential cells (LPTCs) in head-fixed Drosophila walking on an air-supported ball. Cells of the horizontal system (HS)-a subgroup of LPTCs-showed stronger calcium transients in response to visual motion when flies were walking rather than resting. The amplified responses were also correlated with walking speed. Moreover, HS neurons showed a relatively higher gain in response strength at higher temporal frequencies, and their optimum temporal frequency was shifted toward higher motion speeds. Walking-dependent modulation of HS neurons in the Drosophila visual system may constitute a mechanism to facilitate processing of higher image speeds in behavioral contexts where these speeds of visual motion are relevant for course stabilization.
PMID: 20655222 [PubMed - as supplied by publisher]