Combined immunochemistry and live imaging of fluorescent protein expressing neurons in mouse brain

The use of transgenic mice expressing fluorescent proteins to report a specific protein or to identify specific groups of neurons in the brain is revolutionizing many different aspects of neuroscience. Here we use an example of a GFP-expressing reporter mouse from the GENSAT project that allows identification of a specific group of neurons in the mouse cortex. Live GFP detection facilitates identification of the neurons for whole-cell patch clamp electrophysiological recording to probe their functional properties. Post hoc immunohistochemistry allows specific reconstruction of the shape of the recorded neuron; this together with the detection of other co-expressed proteins helps confirm the functional identity of specific neuron types. Approaches such as these are beginning to progress the major task of untangling the complexity of a variety of brain circuits.