MBC Seminar Spring 2018

Malcolm Campbell, Graduate Student, Stanford University, School of Medicine - IDP's - Neurosciences

Principles governing the integration of landmark and self-motion cues in entorhinal cortical codes for navigation.

Abstract: To guide navigation, the nervous system integrates multisensory self-motion and landmark information. We examined how these inputs generate the representation of self-location by recording entorhinal grid, border and speed cells in mice navigating virtual environments. Manipulating the gain between the animal’s locomotion and the visual scene revealed that border cells responded to landmark cues while grid and speed cells responded to combinations of locomotion, optic flow, and landmark cues in a context-dependent manner, with optic flow becoming more influential when it was faster than expected. A network model explained these results, providing principled regimes under which grid cells remain coherent with or break away from the landmark reference frame. Moreover, during path integration-based navigation, mice estimated their position following the principles predicted by our recordings. Together, these results provide a quantitative framework for understanding how landmark and self-motion cues combine during navigation to generate spatial representations and guide behavior.

Amy Christensen, Graduate Student, Stanford University, Department of Biological Sciences and Applied Physics

Running reduces firing but improves coding in rodent higher-order visual cortex.

Abstract: Running profoundly alters stimulus-response properties in mouse primary visual cortex (V1), but its effects in higher-order visual cortex remain under explored. Here we systematically investigated how locomotion modulates visual responses across six visual areas and three cortical layers using a massive dataset from the Allen Brain Institute. Although running has been shown to increase firing in V1, we found that it suppressed firing in higher-order visual areas. Despite this reduction in gain, visual responses during running could be decoded more accurately than visual responses during stationary periods. We show that this effectwas not attributable to changes in noise correlations, and propose that it instead arises from increased reliability of single neuron responses during running.

Amit Goldenberg, Graduate Student, Stanford University, Department of Psychology

Emotional Dynamics as Drivers of Group Behavior

Abstract: Running profoundly alters stimulus-response properties in mouse primary visual cortex (V1), but its effects in higher-order visual cortex remain under explored. Here we systematically investigated how locomotion modulates visual responses across six visual areas and three cortical layers using a massive dataset from the Allen Brain Institute. Although running has been shown to increase firing in V1, we found that it suppressed firing in higher-order visual areas. Despite this reduction in gain, visual responses during running could be decoded more accurately than visual responses during stationary periods. We show that this effectwas not attributable to changes in noise correlations, and propose that it instead arises from increased reliability of single neuron responses during running.