Neuronal representations in the primary visual cortex (V1) are shaped by experience through the integration of both external visual inputs and internal signals related to an animal’s behaviour. The activity of V1 neurons is thus influenced by a variety of factors when animals navigate through their environment. Using in vivo two-photon calcium imaging, we examined the activity of V1 neurons before, during and after head-fixed mice were daily exposed to a visual stimulus that was either associated with a reward or just passively viewed. These results show that neuronal activity in V1 is highly dynamic and changes with the behavioural significance of visual inputs. I will present current projects of the lab related to the mechanisms underlying this plasticity.