Mechanisms of experience dependent plasticity in mouse visual cortex

PROJECT SUMMARY Visual experience plays an important role in shaping the functional organization of the primary visual cortex (V1), both during development and in the mature animal. In adult mice, repeated exposure to a neutral visual stimulus induces long-term adaptation of the evoked sensory response. However, whether this phenomenon also occurs when the stimulus acquires behavioral salience is unknown. In addition, the underlying mechanisms of this form of plasticity are similarly unclear. To address this question, we combine in vivo 2- photon imaging of neuronal activity and glutamatergic signaling with behavioral training and virally-induced genetic manipulation to monitor visually-evoked responses longitudinally across adaptation under different experimental conditions. We will quantify how adaptation shapes the tuning of single neurons to specific features of the visual input and determine whether association of the stimulus with reward alters both synaptic and cellular plasticity during repeated stimulus delivery. Finally, we will identify the role of NMDA-type glutamate receptors in experience-dependent adaptation and synaptic plasticity in vivo. Our results will provide critical new insight into the relationship between sensory experience, synaptic plasticity, and visual representations in the neocortex.