title: Random positions of dendritic spines in human cerebral cortex.
abstract: Dendritic spines establish most excitatory synapses in the brain and are located in Purkinje cell's dendrites along helical paths, perhaps maximizing the probability to contact different axons. To test whether spine helixes also occur in neocortex, we reconstructed >500 dendritic segments from adult human cortex obtained from autopsies. With Fourier analysis and spatial statistics, we analyzed spine position along apical and basal dendrites of layer 3 pyramidal neurons from frontal, temporal, and cingulate cortex. Although we occasionally detected helical positioning, for the great majority of dendrites we could not reject the null hypothesis of spatial randomness in spine locations, either in apical or basal dendrites, in neurons of different cortical areas or among spines of different volumes and lengths. We conclude that in adult human neocortex spine positions are mostly random. We discuss the relevance of these results for spine formation and plasticity and their functional impact for cortical circuits.
authors: Cajal Blue Brain Project, Escuela Técnica Superior de Ingenieros Informáticos, Universidad Politécnica de Madrid, Campus Montegancedo S/N, 28223 Madrid, Spain.
authors: Juan
authors: J
authors: Morales
authors: Instituto Cajal, 28002 Madrid, Spain, Laboratorio Cajal de Circuitos Corticales, Universidad Politécnica de Madrid, Campus de Montegancedo s/n, 28223 Madrid, Spain.
authors: Ruth
authors: R
authors: Benavides-Piccione
authors: Department of Biological Sciences, Columbia University, New York, New York 10027.
authors: Mor
authors: M
authors: Dar
authors: Laboratorio Cajal de Circuitos Corticales, Universidad Politécnica de Madrid, Campus de Montegancedo s/n, 28223 Madrid, Spain.
authors: Isabel
authors: http://orcid.org/0000-0003-2391-0704
authors: I
authors: Fernaud
authors: Departamento de Arquitectura y Tecnología de Sistemas Informáticos, Escuela Técnica Superior de Ingenieros Informáticos, Universidad Politécnica de Madrid, Campus de Montegancedo s/n, 28660 Madrid, Spain, and.
authors: Angel
authors: A
authors: Rodríguez
authors: Departamento de Inteligencia Artificial, Escuela Técnica Superior de Ingenieros Informáticos, Universidad Politécnica de Madrid, Campus de Montegancedo s/n, 28660 Madrid, Spain.
authors: Laura
authors: L
authors: Anton-Sanchez
authors: Departamento de Inteligencia Artificial, Escuela Técnica Superior de Ingenieros Informáticos, Universidad Politécnica de Madrid, Campus de Montegancedo s/n, 28660 Madrid, Spain.
authors: Concha
authors: C
authors: Bielza
authors: Departamento de Inteligencia Artificial, Escuela Técnica Superior de Ingenieros Informáticos, Universidad Politécnica de Madrid, Campus de Montegancedo s/n, 28660 Madrid, Spain.
authors: Pedro
authors: P
authors: Larrañaga
authors: Instituto Cajal, 28002 Madrid, Spain, Laboratorio Cajal de Circuitos Corticales, Universidad Politécnica de Madrid, Campus de Montegancedo s/n, 28223 Madrid, Spain.
authors: Javier
authors: J
authors: DeFelipe
authors: Department of Biological Sciences, Columbia University, New York, New York 10027, rmy5@columbia.edu.
authors: Rafael
authors: R
authors: Yuste
mesh_terms: D000328:Adult; D000369:Aged, 80 and over; D002540:Cerebral Cortex / Q000166:cytology / Q000502:physiology / Q000648:ultrastructure*; D049229:Dendritic Spines / Q000502:physiology / Q000648:ultrastructure*; D005583:Fourier Analysis; D006801:Humans; D008297:Male; D019579:Neocortex / Q000166:cytology / Q000000981:diagnostic imaging; D017966:Pyramidal Cells / Q000166:cytology / Q000648:ultrastructure; D014463:Ultrasonography
keywords: Fourier; Lucifer; intracellular injections; pyramidal cells; spatial distribution