In this webinar we explore the use of probes beyond the central nervous system... Joze Guzman (Institute of Molecular Biology, Austria) presents a unique insight in to the emerging field of human brain organoids and describes how he has optimised this preparation for single unit recording with optogenetic identification. In tandem, Roberto Lopez (University of Michigan) shows how he has used our probes to uncover highly novel single unit functional organisation within the adrenal medulla during stress responses in rats.