An increase in spontaneous activity mediates visual habituation

The cerebral cortex is spontaneously active, but the function of this ongoing activity remains unclear. To test whether spontaneous activity encodes learned experiences, we measured the response of neuronal populations in mouse primary visual cortex with chronic two-photon calcium imaging during visual habituation to a specific oriented stimulus. We find that, during habituation, spontaneous activity increases in neurons across the full range of orientation selectivity, eventually matching that of evoked levels. This increase in spontaneous activity robustly correlates with the degree of habituation. Moreover, boosting spontaneous activity with two-photon optogenetic stimulation to the levels of visually evoked activity accelerates habituation. Our study shows that cortical spontaneous activity is linked to habituation, and we propose that habituation unfolds by minimizing the difference between spontaneous and stimulus-evoked activity levels. We conclude that baseline spontaneous activity could gate incoming sensory information to the cortex based on the learned experience of the animal. [Display omitted] •Mice behaviorally habituate to repeated visual stimuli•Spontaneous activity, not visually evoked activity, increases after habituation•This increase in spontaneous activity robustly correlates with habituation•Boosting spontaneous activity with two-photon stimulation accelerates habituation The cerebral cortex is spontaneously active. Miller et al. find that spontaneous cortical activity increases after a visual habituation, a simple form of learning. Furthermore, boosting spontaneous activity with optogenetics is sufficient to accelerate visual habituation. This reveals a direct role of spontaneous cortical activity in visual learning.