Invited Session IV: Studies of the visual cortex with sub-millimeter resolution: Development of natural scene processing continues after the critical period for ocular dominance plasticity closes.

Abstract

The development of the visual system is known to be shaped by early-life experience. How complex responses to naturalistic scenes emerge from neurons that are innately tuned to simple orientations is an active area of investigation. Using 2-photon calcium in awake mice, we found that natural scene discriminability increases by 75% between the ages of 4 to 6 weeks in primary visual cortex. This increase in decoding accuracy is accompanied by a shift in neuronal preference towards natural scenes. Natural scene discriminability, therefore, continues to improve past the peak of the critical period for ocular dominance plasticity at postnatal day (p) 28. Notably visual deprivation specifically from p28 to p42 interfered with the full development of this preference shift and impaired natural scene decoding accuracy. We are currently exploring the circuit basis for this protracted development. We speculate that a sequential progression in which neurons first prefer simple stimuli such as oriented bars of light (grating stimuli) prior to the development of selectivity for complex features may help ensure that the spatial organization of receptive fields is maintained as the system becomes refined to represent salient visual cues as animals expand their behavioral repertoire and learn to navigate complex environments.