Abstract
Brief monocular deprivation during a developmental critical period, but not thereafter, alters the receptive field properties (tuning) of neurons in visual cortex, but the characteristics of neural circuitry that permit this experience-dependent plasticity are largely unknown. We performed repeated calcium imaging at neuronal resolution to track the tuning properties of populations of excitatory layer 2/3 neurons in mouse visual cortex during or after the critical period, as well as in nogo-66 receptor (ngr1) mutant mice that sustain critical-period plasticity as adults. The instability of tuning for populations of neurons was greater in juvenile mice and adult ngr1 mutant mice. We propose instability of neuronal tuning gates plasticity and is directed by experience to alter the tuning of neurons during the critical period.