Clustered cortical organization and the enhanced probability of intra-areal functional integration.
Similarly responsive neurons organize into submillimeter-sized clusters (domains) across many neocortical areas, notably in Areas V1 and V2 of primate visual cortex. While this clustered organization may arise from wiring minimization or from self-organizing development, it could potentially support important neural computation benefits. Here, we suggest that domain organization offers an efficient computational mechanism for intra-areal functional integration in certain cortical areas and hypothesize that domain proximity could support a higher-than-expected spatial correlation of their respective terminals yielding higher probabilities of integration of differing domain preferences. To investigate this hypothesis we devised a spatial model inspired by known parameters of V2 functional organization, where neighboring domains prefer either colored or oriented stimuli. Preference-selective joint probabilities were calculated for model terminal co-occurrence with configurations encompassing diverse domain proximity, shape, and projection. Compared to random distributions, paired neighboring domains (< or =1200 microm apart) yielded significantly enhanced coincidence of terminals converging from each domain. Using this reference data, a second larger-scale model indicated that V2 domain organization may accommodate relatively complete sets of intra-areal color/orientation integrations. Together, these data indicate that domain organization could support significant and efficient intra-areal integration of different preferences and suggest further experiments investigating prevalence and mechanisms of domain-mediated intra-areal integration.
Cooper
C Garret
CG
Department of Neurobiology and Anatomy, and Sensory Neuroscience Research Center, West Virginia University School of Medicine, USA.
Ramsden
Benjamin M
BM
D000818:Animals; D002449:Cell Aggregation / Q000502:physiology; D016000:Cluster Analysis; D019295:Computational Biology / Q000379:methods; D006801:Humans; D008251:Macaca; D008959:Models, Neurological; D009415:Nerve Net / Q000166:cytology / Q000502:physiology*; D009434:Neural Pathways / Q000166:cytology / Q000502:physiology*; D009474:Neurons / Q000166:cytology / Q000502:physiology*; D011336:Probability; D011897:Random Allocation; D014793:Visual Cortex / Q000166:cytology / Q000502:physiology*; D014795:Visual Pathways / Q000502:physiology