Technical Program

Paper Detail

Paper: RS-1A.1
Session: Late Breaking Research 1A
Location: Late-Breaking Research Area
Session Time: Thursday, September 6, 16:30 - 18:30
Presentation Time:Thursday, September 6, 16:30 - 18:30
Presentation: Poster
Paper Title: Somatic and dendritic calcium imaging of mouse retrosplenial cortex during volitional head rotation in 2-D navigation
Authors: Jakob Voigts, Mark Harnett, MIT, United States
Abstract: Efficient navigation requires the context-dependent integration of a multitude of signals. A familiar landmark on an animal's right side, for instance, has a different meaning depending on whether the animal is facing north or south. Retrosplenial cortex (RSC) has been proposed to serve a central role in solving such computations by translating between egocentric and allocentric representations of the environment. Mixed representations in RSC neurons, in which individual inputs can change the interpretation of others, form a convenient model system for studying associative neuronal computations. Here, we examine the subcellular computations underlying the encoding of heading direction in RSC using calcium imaging in mice exploring a physical 2-d environment. We developed an experimental approach that permits mice to freely rotate their heads in the azimuthal plane with negligible inertia and friction during conventional 2-photon imaging. We used this system to perform GCaMP imaging at somas and dendrites of pyramidal neurons in retrosplenial cortex. Our findings indicate that individual RSC neurons receive a variety of tuned inputs in their apical dendrites, that are nonlinearly modulated by other inputs before influencing somatic output. Our results provide insight into the role of dendritic computations in head-direction encoding in RSC and will provide a starting point for studying more general associative dendritic computations.