McNaughton, Bruce

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https://opus.uleth.ca/handle/10133/4737

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Browsing McNaughton, Bruce by Author "Clark, Benjamin J."

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    Cortical connectivity maps reveal anatomically distinct areas in the parietal cortex of the rat
    (Frontiers Media, 2014) Wilber, Aaron A.; Clark, Benjamin J.; Demecha, Alexis J.; Mesina, Lilia; Vos, Jessica M.; McNaughton, Bruce L.
    A central feature of theories of spatial navigation involves the representation of spatial relationships between objects in complex environments. The parietal cortex has long been linked to the processing of spatial visual information and recent evidence from single unit recording in rodents suggests a role for this region in encoding egocentric and world-centered frames. The rat parietal cortex can be subdivided into four distinct rostral-caudal andmedial-lateral regions,which includesazonepreviously characterized as secondary visual cortex. At present, very little is known regarding the relative connectivity of these parietal subdivisions. Thus, we set out to map the connectivity of the entire anterior-posterior and medial-lateral span of this region. To do this we used anterograde and retrograde tracers in conjunction with open source neuronal segmentation and tracer detection tools to generate whole brain connectivity maps of parietal inputs and outputs. Our present results show that inputs to the parietal cortex varied significantly along the medial-lateral, but not the rostral-caudal axis. Specifically, retrosplenial connectivity is greater medially, but connectivity with visual cortex, though generally sparse, is more significantlaterally.Finally,basedonconnectiondensity,theconnectivitybetweenparietal cortex and hippocampus is indirect and likely achieved largely via dysgranular retrosplenial cortex. Thus, similar to primates, the parietal cortex of rats exhibits a difference in connectivity along the medial-lateral axis, which may represent functionally distinct areas.
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    Interaction of egocentric and world-centered reference frames in the rat posterior parietal cortex
    (Society for Neuroscience, 2014) Wilber, Aaron A.; Clark, Benjamin J.; Forster, Tyler C.; Tatsuno, Masami; McNaughton, Bruce L.
    Navigation requires coordination of egocentric and allocentric spatial reference frames and may involve vectorial computations relative to landmarks. Creation of are presentation of target heading relative to landmarks could be accomplished from neurons that encode the conjunction of egocentric landmark bearings with allocentric head direction. Landmark vector representations could then be created by combining these cells with distance encoding cells. Landmark vector cells have been identified in rodent hippocampus. Given remembered vectors at go allocations, it would be possible to use such cells to compute trajectories to hidden goals. To look for the first stage in this process, we assessed parietal cortical neuralactivity as a function of egocentric cue light location and allocentric head direction in rats running a random sequence to light locations around a circular platform. We identified cells that exhibit the predicted egocentric-by allocentric conjunctive characteristics and anticipate orienting toward the goal.