Characterization of receptive fields of mouse retinal ganglion cells through comparative analysis of spike-triggered average and spike-triggered covariance

摘要

Structural correlates of modular organization of activity propagation in the primate somatosensory cortex Axonal connections of column size cortical regions exhibit patchy distribution all over the primate cerebral cortex. The axonal patches represent specific target sites as e.g. columns of similar orientation preference in the visual cortex. However, axonal connections also densely distribute outside of the patches without any apparent grouping. Instead, the out-patch axons exhibit a radial spreading from the origin towards probably distant target sites including the patches. Interestingly both patch and out-patch axons form axon terminal-like structures suggesting their role in synaptic transmission. However, it is not known whether axons play a similar role in the propagation of activity and dissemination of information within and outside of the patches. To answer this question morphological properties of reconstructed axons within and outside the patches were compared for intra- and inter-areal of connections in the somatosensory cortex of squirrel monkeys. Our preliminary findings suggest that axons have similar tortu- osity but different bouton density within and out of the patches. Specifically, intrinsic connections exhibit higher bouton density within than outside of the patches. The increased bouton density within the patch accompanied by extensive axonal convergence could result in a highly efficient way of signal transmission in terminal arborization patches of the cerebral cortex.