The representation of space in the brain

Abstract

Animals can navigate vast distances and often display behaviours or activities that indicate a detailed, internal spatial representation of their surrounding environment or a 'cognitive map'. Over a century of behavioural research on spatial navigation in humans and animals has greatly increased our understanding of how this highly complex feat is achieved. In turn this has inspired half a century of electrophysiological spatial navigation and memory research which has further advanced our understanding of the brain. In particular, three functional cell types have been suggested to underlie cognitive mapping processes; place cells, head direction cells and grid cells. However, there are numerous other spatially modulated neurons in the brain. For a more complete understanding of the electrophysiological systems and behavioural processes underlying spatial navigation we must also examine these lesser understood neurons. In this review we will briefly summarise the literature surrounding place cells, head direction cells, grid cells and the evidence that these cells collectively form the neural basis of a cognitive map. We will then review literature covering many other spatially modulated neurons in the brain that perhaps further augment this cognitive map.

Object-vector coding in the medial entorhinal cortex

“…The hippocampus and the medial entorhinal cortex are part of a brain system for mapping of self-location that is likely recruited when animals navigate between locations in the proximal environment [1][2][3][4][5] . In the hippocampus, place cells fire specifically when the animal is at certain places 6,7 , and goal-vector cells encode the animal's movement in the direction of a goal 8,9 . Collectively, intermixed assemblies of place cells and goal-vector cells may create maps of the animal's present and future position in the local environment 1,10 .…”

On the Value of Reptilian Brains to Map the Evolution of the Hippocampal Formation

“…For studies on cortical volume changes in relation to spatial navigation [Day et al, 1999;Ladage et al, 2009] we direct the reader to excellent reviews that also incorporate a broader phylogenetic perspective [Roth et al, 2010;Broglio et al, 2015;Murray et al, 2016;Striedter, 2016;Bingman et al, 2017]. Similarly, we omit studies on cortical interneurons in reptiles [reviewed in Reiner, 1991;Guirado and Davila, 1999;Naumann and Laurent, 2017], since, despite extensive knowledge about cell type diversity of mammalian hippocampal interneurons, their function remains poorly understood [Grieves and Jeffery, 2017].…”

Spiking Neural Network on Neuromorphic Hardware for Energy-Efficient Unidimensional SLAM

“…We developed a recursive SNN that suggests a cueintegration connectome performing head direction localization and mapping, and we integrated the network to Loihi. Inspired by the spatial navigation system found in the mammalian brain, the head direction and border cells in our network exhibited biologically realistic activity [6]. Our model had intrinsic asynchronous parallelism by incorporating spiking neurons, multi-compartmental dendritic trees, and plastic synapses, all of which are supported by Loihi.…”

“…Interestingly, efficient and highly accurate localization and mapping are "effortless" characteristics of mammalian brains [5]. Over the last few decades, a number of specialized neurons, including border cells, head direction cells, place cells, grid cells, and speed cells, have been found to be part of a brain network that solves localization and mapping [6] in an energy-efficient manner [7].…”