Topic: binocular V1

The primary visual cortex (V1) of higher mammals such as cats and monkeys shows columns for stimulus features like orientation preference and ocular dominance, but such columns are not found in all groups of mammals. Models suggest that the afferent sampling density in V1 could be a key factor determining whether a columnar organization is established or not. Accordingly, in rodent V1, which – in comparison to other animals – has a low sampling density, there appear to be no orientation columns. However, the situation is less clear for ocular dominance. So far, in vivo imaging studies in mice

Monocular deprivation (MD), the temporary closure of one eye, shifts neuronal responses in the visual cortex towards the open eye. This functional change is accompanied by formation of new dendritic spines. However, the presynaptic partners of these new spines have not yet been identified. Here we introduce a novel approach, two-timeframe monosynaptic rabies virus tracing, to survey the whole brain for new inputs associated with ocular dominance (OD) plasticity.First, in a tdTomato reporter mouse we infect starter cells (expressing a helper construct) with a rabies virus carrying eGFP and indu