Functional Circuit Mapping with Optogenetics

The anatomical and imaging approaches described above still do not concretely demonstrate how information passes through the brain circuits.  To address this, we need to test the functional relationships among the cells that we are studying.  For this, we turn to optogenetics.   By driving activity specifically in one brain region that we are interested in, and performing calcium imaging of the neurons in another region that may be connected, we can see whether and in what way one region’s activity affects cells in the downstream region.  Given the complex and interconnected nature of the nervous system, this does not necessarily mean that the stimulated cells and the responsive cells are synaptic partners (anatomical mapping is needed for that), but it does establish a functional relationship between one region and another.

Here, our capabilities in optical physics play an important role in our optogenetic approaches. By creating customised holograms to illuminate very specific circuit elements, we aim to carry out incisive manipulations that will shed light on the circuits’ functional architecture.