EN
Multiphoton-imaging allows unambiguous access to neuronal populations and neuronal substructures located well below the cortical surface. In combination with genetically encoded activity indicators this approach can be used to infer spiking activity from neuronal populations in the awake animal, with single cell and single action-potential accuracy. For this lecture I will present imaging tools that are necessary to accurately record activity from neuronal populations in the awake behaving animal using the multi-photon excitation principle. I will also outline strategies that have allowed access to neuronal activity in the freely moving animal and in deep cortical layers. In addition, I will outline recent strategies to simultaneously track the precise head and eye positions of freely behaving animals.