Tracking Tau in Neurons: How to Transfect and Track Exogenous Tau into Primary Neurons.

Primary neurons have proved to be an essential tool for investigating neuronal polarity in general and polarized Tau distribution in particular. However, mature primary neurons are notoriously difficult to transfect with nonviral vectors and are very sensitive both to cytoskeletal manipulation and to imaging. Common nonviral transfections require the use of a monolayer of supportive glia or high density cultures, both of which complicate imaging. Here, we provide a simple nonviral transfection method enabling transfection of Tau to achieve expression levels comparable to endogenous Tau. This allows to investigate specific effects on, e.g., distribution and transport of Tau, without grossly affecting other cytoskeleton-based parameters such as microtubule density or microtubule-based transport.