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Dr. Ryan Yoder
Department of Psychology
Indiana University – Purdue University Fort Wayne
The neural representation of directional heading is carried by head direction cells located in several brain regions. Surgical lesions to these brain regions impair navigation in darkness, suggesting involvement of head direction cells in non-visual navigation. However, these lesions often disrupt additional brain signals, and this collateral damage may underlie the observed navigation deficits. We therefore tested whether the head direction signal contributes to navigation in otoconia-deficient tilted mice, which have intact brains, but degraded head direction signals. Homozygous tilted mice and their heterozygous control littermates performed a Lashley III maze across five trials in darkness, which forces animals to rely on self-movement (idiothetic) cues to guide navigation. Performance measures included latency to reach the food reward and number of errors, which included incorrect turns or turning around in an alley. The heterozygous control mice showed gradual performance improvements across five trials, whereas tilted mice showed a greater number of errors and greater latency to complete the task. Surprisingly, tilted mice improved abruptly during the last two trials. These results suggest that the head direction signal is related to the use of idiothetic cues for navigation.
Psychology | Social and Behavioral Sciences
Harvey, Ryan, "The Head Direction Signal Contributes to Accurate Navigation in Darkness" (2013). 2013 IPFW Student Research and Creative Endeavor Symposium. 26.