Spatially Periodic Activation Patterns of Retrosplenial Cortex Encode Route Sub-spaces and Distance Traveled

Abstract

Traversal of a complicated route is often facilitated by considering it as a set of related sub-spaces. Such compartmentalization processes could occur within retrosplenial cortex, a structure whose neurons simultaneously encode position within routes and other spatial coordinate systems. Here, retrosplenial cortex neurons were recorded as rats traversed a track having recurrent structure at multiple scales. Consistent with a major role in compartmentalization of complex routes, individual retrosplenial cortex (RSC) neurons exhibited periodic activation patterns that repeated across route segments having the same shape. Concurrently, a larger population of RSC neurons exhibited single-cycle periodicity over the full route, effectively defining a framework for encoding of sub-route positions relative to the whole. The same population simultaneously provides a novel metric for distance from each route position to all others. Together, the findings implicate retrosplenial cortex in the extraction of path sub-spaces, the encoding of their spatial relationships to each other, and path integration.

A neural-level model of spatial memory and imagery

“…Future work should try to integrate the present account of spatial cognition with recent progress concerning spatial coding in parietal areas (Nitz, 2006; Nitz, 2009; Nitz, 2012; Harvey et al, 2012; Whitlock et al, 2012; Raposo et al, 2014; Vedder et al, 2017), and a broader view of retrosplenial function (e.g., Alexander and Nitz, 2015; Alexander and Nitz, 2017). Notably, BVCs were predicted by an early predecessor of the present model (Hartley et al, 2000; Burgess et al, 2001a).…”

Three brain states in the hippocampus and cortex

“…Second, a form of generalization termed pattern completion is commonly ascribed to be function of the highly recurrent neural network in CA3 (reviewed in Le Duigou, Simonnet, Telenczuk, Fricker, and Miles (); Knierim and Neunuebel ()); recent studies include Neunuebel and Knierim (); Lee et al (); Lu et al ()). Third, past work has shown that brain regions beyond the hippocampus encode similarities across spatial‐navigational experience (e.g., prefrontal [Jung, Qin, McNaughton, & Barnes, ], parietal [Nitz, ], retrosplenial [Alexander & Nitz, ; Alexander & Nitz, ], and entorhinal cortex [Frank et al, ; Derdikman et al, ]; discussion in [Grieves, Duvelle, Wood, & Dudchenko, ]). These brain regions can thus contribute spatially abstractive neural activity to target structures, among them the hippocampus.…”

Dissociating Landmark Stability from Orienting Value Using Functional Magnetic Resonance Imaging

“…In recent years there has been increased interest in characterizing the features of landmarks, in particular seeking to identify those traits that are helpful for building environmental representations and that facilitate effective wayfinding (Auger, Zeidman, & Maguire, 2017; Marchette, Vass, Ryan, & Epstein, 2015; Auger & Maguire, 2013; Auger, Mullally, & Maguire, 2012; Konkle & Oliva, 2012; Lew, 2011; Yoder, Clark, & Taube, 2011; Galati, Pelle, Berthoz, & Committeri, 2010; Committeri et al, 2004; Janzen & van Turennout, 2004). The brain areas that process these landmark features have also begun to be scrutinized with a view to understanding the neural evolution of environmental representations and the mechanisms involved (Alexander & Nitz, 2017; Auger et al, 2017; Chrastil, Sherrill, Aselcioglu, Hasselmo, & Stern, 2017; Mao, Kandler, McNaughton, & Bonin, 2017; Vedder, Miller, Harrison, & Smith, 2017; Shine, Valdés-Herrera, Hegarty, & Wolbers, 2016; Auger, Zeidman, & Maguire, 2015; Baumann & Mattingley, 2013; Aggleton, 2010; Iaria, Chen, Guariglia, Ptito, & Petrides, 2007; Wolbers, Weiller, & Büchel, 2004). …”