JournalNeural Excitability, Synapses, and Glia

Local Order within Global Disorder: Synaptic Architecture of Visual Space

This image shows the dendritic locations of a subset of spines. Each spine is colored to indicate the group label from k-means clustering; the group label from k-means clustering is also indicated next to each spine. The synaptic clusters convey functionally distinct spatial receptive field properties.

Substantial evidence at the subcellular level indicates that the spatial arrangement of synaptic inputs onto dendrites could play a significant role in cortical computations, but how synapses of functionally defined cortical networks are arranged within the dendrites of individual neurons remains unclear. Here we assessed one-dimensional spatial receptive fields of individual dendritic spines within individual layer 2/3 neuron dendrites. Spatial receptive field properties of dendritic spines were strikingly diverse, with no evidence of large-scale topographic organization. At a fine scale, organization was evident: neighboring spines separated by less than 10 μm shared similar spatial receptive field properties and exhibited a distance-dependent correlation in sensory-driven and spontaneous activity patterns. Fine-scale dendritic organization was supported by the fact that functional groups of spines defined by dimensionality reduction of receptive field properties exhibited non-random dendritic clustering. Our results demonstrate that functional synaptic clustering is a robust feature existing at a local spatial scale.

Scholl B, Wilson D, and Fitzpatrick D. Local Order within Global Disorder: Synaptic Architecture of Visual Space. Neuron. Published online November 2, 2017.