" The inertial navigation system of the mammalian brain: wiring diagram and internal dynamics "
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Abstract:Mammals can encode relative spatial location, without reference to external cues, by neural integration of linear and angular self-motion ('path integration').  The neural machinery underlying this function appears to be located in the hippocampal formation and one of its main cortical afferent systems, the medial entorhinal cortex.  These structures generate a map-like system of spatial coordinates, encoded by neural populations whose connections give rise to a 2-dimensional "attractor map" on which a 'bump'

of cooperative neural activity moves in accordance with the movements of the animal in its environment.  Directional information is provided by a system of "head-direction" cells which integrate head angular velocity to give relative head orientation.  The scale of the coordinate system increases systematically from the septal to temporal poles, apparently because of a systematic variation in the gain of a movement-speed signal. The unique, periodic synaptic matrix that accomplishes path integration may be self-organized in early development through a simple symmetry breaking operation coupled with competitive learning.