Experience with moving visual stimuli drives the early development of cortical direction selectivity

Abstract

The onset of vision occurs when neural circuits in the visual cortex are immature, lacking both the full complement of connections and the response selectivity that defines functional maturity. Direction-selective responses are particularly vulnerable to the effects of early visual deprivation, but it remains unclear how stimulus-driven neural activity guides the emergence of cortical direction selectivity. Here we report observations from a motion training protocol that allowed us to monitor the impact of experience on the development of direction-selective responses in visually naive ferrets. Using intrinsic signal imaging techniques, we found that training with a single axis of motion induced the rapid emergence of direction columns that were confined to cortical regions preferentially activated by the training stimulus. Using two-photon calcium imaging techniques, we found that single neurons in visually naive animals exhibited weak directional biases and lacked the strong local coherence in the spatial organization of direction preference that was evident in mature animals. Training with a moving stimulus, but not with a flashed stimulus, strengthened the direction-selective responses of individual neurons and preferentially reversed the direction biases of neurons that deviated from their neighbours. Both effects contributed to an increase in local coherence. We conclude that early experience with moving visual stimuli drives the rapid emergence of direction-selective responses in the visual cortex. ©2008 Macmillan Publishers Limited. All rights reserved.