The velocity of objects traveling along compound trajectories affects firing properties of an identified locust motion-sensitive interneuron

Abstract

Event Abstract Back to Event The velocity of objects traveling along compound trajectories affects firing properties of an identified locust motion-sensitive interneuron Jack Gray1* and Paul Dick1 1 University of Saskatchewan, Biology, Canada The descending contralateral movement detector (DCMD) is a neuron in the locust visual system that is implicated in controlling escape behavior and is known to encode a ratio of the size and velocity of an object approaching along a single, collision trajectory. Recent studies suggest that the DCMD is also capable of encoding more complex visual information resulting from objects that transition to or from looming trajectories. However, the putative effects of object velocity have not yet been tested for these compound trajectories. We presented locusts with objects moving at different velocities along trajectories that transition to looming within different regions of the locust’s visual field. Concomitant extracellular DCMD recordings were analyzed to determine if firing rate modulation was correlated with disc expansion properties that reflect transition time and location. Transient translating to looming stimuli evoked two local maxima in firing rate- an early, broad and low peak that was followed by a decrease in firing rate associated with the time of transition between translating and looming, increasing in to a higher, primary peak just before the projected time of collision. The characteristics of the primary peak are consistent with the previously reported response of the DCMD to a looming visual stimulus; the timing of the peak was closer to the time of collision and the peak was narrower for higher velocity objects. Novel results show a correlation between the timing of the temporary decrease in firing rate and the time of transition for high velocity objects, but not for lower velocities. In addition, the difference between the height of the early peak and the depth of the following valley was less for objects travelling at higher velocities. These results, among others, may indicate that the DCMD is able to encode more visual information than previously though. In particular, this seems to be the case for objects moving at higher velocities, which would require a more immediate behavioural response in the natural environment of a flying locust. Keywords: insect, Locust, motion detection, Vision Conference: Tenth International Congress of Neuroethology, College Park. Maryland USA, United States, 5 Aug - 10 Aug, 2012. Presentation Type: Poster Presentation (see alternatives below as well) Topic: Sensory: Vision Citation: Gray J and Dick P (2012). The velocity of objects traveling along compound trajectories affects firing properties of an identified locust motion-sensitive interneuron. Conference Abstract: Tenth International Congress of Neuroethology. doi: 10.3389/conf.fnbeh.2012.27.00353 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 30 Apr 2012; Published Online: 07 Jul 2012. * Correspondence: Dr. Jack Gray, University of Saskatchewan, Biology, Saskatoon, Canada, jack.gray@usask.ca Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Jack Gray Paul Dick Google Jack Gray Paul Dick Google Scholar Jack Gray Paul Dick PubMed Jack Gray Paul Dick Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.