Abstract
Direction-selective columns in the visual cortex, which respond preferentially to visual stimulus moving in a given direction, develop rapidly during a critical period shortly after eye opening. Direction-selectivity in the cortex requires visual experience for proper development, but the precise mechanisms underlying this change and extent to which visual stimulus can affect the properties of direction-selective cells are still largely unknown. A mature cortical cell’s receptive field properties can be predicted largely based on initial biases that are present prior to eye-opening, suggesting a permissive role for visual experience (Roy et al. 2018). However, these initial biases can be weakened or overridden by training with visual stimulus moving in a single direction (Van Hooser et al. 2012). Here, we show that plasticity within the cortex can account for the permissive changes in direction-selectivity seen during the critical period, where cortical cells become increasingly selective for a direction in which they had a small initial bias. On the other hand, plasticity between LGN cells and the cortex is required to explain instructive changes like a shift in the cell’s preferred direction. Furthermore, we provide evidence that a rise in inhibition is required to stabilize the behavior of cortical cells and maintain selectivity despite plastic inputs.