Model-based spatial navigation in the hippocampus-ventral striatum circuit: A computational analysis
Fig 1
Spatial navigation in rodents: functional organization, scenario, and overall architecture of the model.
(A) Structures in the rodent brain that are involved in goal-directed navigation. HC-VS constitute the essential structures of the putative model-based control system, which supports goal-directed behavior. AT and MEC provide input to the model-based control system. Output of the HC-VS circuitry may reach the cortex/mPFC via VP and MD. (B) The Y-maze used here and in [19]. Each room contains 3 goal locations, which can be cued with a light with different probability in three different phases (separate panels) according to the color legend. See the main text for more explanation. (C) Sample grid cells providing systematic (spatial) information about the environment. (D) Architecture of our biologically inspired model-based reinforcement-learning model for spatial navigation that combines non-parametric clustering of the input signal Pc(s|x), a state-transition model PM(s′|s,a), and a state-value model PV(r|g,s) with lookahead prediction mechanism for learning and control. See the Methods for details. Abbreviations: AT, anterior thalamus; HC, hippocampus; MD, mediodorsal thalamus; MEC, medial entorhinal cortex; mPFC, medial prefrontal cortex, VP, ventral pallidum, VS, ventral striatum.