Optical window for visualization of peripheral nerves in animal models

In vivo imaging of a nerve injury and longitudinal monitoring of peripheral nerve processes in preclinical models can shed light on many biological process within the nerve. Optical imaging with its high spatial and temporal resolution is highly promising, however high scattering from the skin and other adjacent organs such as muscle limit the application to only in vitro or ex vivo studies. To address these limiting issues, we developed a minimally invasive in vivo model that enables continuous imaging of a peripheral nerve with a high, single axon resolution. Our approach uses a flexible skin-imbedded transparent optical window with the nerve surgically repositioned above the muscle layer. This modality allows longitudinal single-axonal resolution microscopy of the nerve with virtually any optical reporter that can be used in living animals.