In-vivo optogenetics and pharmacology in deep intracellular recordings

Single cell intracellular recordings in-vivo at deep brain structures are seldomly accompanied by nearby optogenetics or drug application. The use of such tools is limited as both light and drugs cannot penetrate deep inside brain tissue. Hence, the optical fiber or drug delivery pipette needs to be placed within the brain close to the recording pipette. So far, however, this has required highly accurate hardware to achieve. These complications have now been solved by new approaches enabling intracellular recordings both for optogenetics and pharmacological application by the use of a single manipulator. In this manuscript we review these technologies - their pros, cons and implications.