Spatial clustering of orientation preference in primary visual cortex of the large rodent agouti

ABSTRACT: Summary All rodents investigated so far possess orientation-selective neurons in the primary visual cortex (V1) but – in contrast to carnivores and primates – no evidence of periodic maps with pinwheel-like structures. Theoretical studies debating whether phylogeny or universal principles determine development of pinwheels point to V1 size as a critical constraint. Thus, we set out to study maps of agouti, a big diurnal rodent with a V1 size comparable to cats'. In electrophysiology, we detected interspersed orientation and direction-selective neurons with a bias for horizontal contours, corroborated by homogeneous activation in optical imaging. Compatible with spatial clustering at short distance, nearby neurons tended to exhibit similar orientation preference. Our results argue against V1 size as a key parameter in determining the presence of periodic orientation maps. They are consistent with a phylogenetic influence on the map layout and development, potentially reflecting distinct retinal traits or interspecies differences in cortical circuitry. Graphical abstract Highlights • Agouti V1 neurons are among the highest orientation- and direction-selective neurons in rodents• They respond best to low spatial frequencies and with a bias for horizontal orientations• There is no evidence of systematic periodic maps of orientation columns for agouti• Neurons along the vertical cortical axis tend to have similar orientation preferences Biological Sciences; Neuroscience; Developmental Neuroscience; Cellular Neuroscience; Sensory Neuroscience

SUBMITTER: Ferreiro D 

PROVIDER: S-EPMC7744940 | biostudies-literature | 2020 Dec

REPOSITORIES: biostudies-literature