Journal: Nature Communications

Article Title: Enabling comprehensive optogenetic studies of mouse hearts by simultaneous opto-electrical panoramic mapping and stimulation

doi: 10.1038/s41467-021-26039-8

Figure Lengend Snippet: a The heart container geometry was derived from adult mouse hearts (left) undergoing photogrammetry (center) with results being approximated by a tri-axial ellipsoid (right; prospective sensor locations indicated by green lines). b Design of one container half. c Left: for probe assembly, the container half (yellow) was temporarily fixed to a 3D-printed heart model (red) that aligned the probe tips during mounting to the prospective heart surface. Center: container with inserted probes (green: optical, red: electrical) with magnification depicting the fluid layer beneath the probes (blue arrow). Right: image of the fully assembled container half (bright discs: illuminated optical fibers, black discs: electrodes). d Left: visualization of one-half of the platform assembly with printed circuit board (PCB) holder, fluid reservoir, and organ container. Right: fully assembled POEMS system. e System overview. Left: the 64 electrical probes are connected to a dedicated recording/stimulation system. Center: the faceplate of the combined 294 optical light guides (OLG) is fixed by a holder (OLG H ) to the image plane of a tandem-lens epifluorescence macroscope (HAL halogen lamp, HM hot mirror, SHR shutter, ECF excitation filter, DM dichroic mirror, EMF emission filter, OBJ1,2 macroscope objectives, CAM camera). Right, center: view of the OLG faceplate with gray and colored fiber stacks belonging to one container half each. Horizontally aligned fibers follow coronal sections of the container (upper schematic). The enlargement shown at the bottom depicts the assignment of sensor pixels to individual fibers and illustrates an example of a 3 × 3 pixel array capturing the light from a single optical fiber.

Article Snippet: The OLG was mounted in the focal plane of a custom-made 1× tandem-lens epifluorescence macroscope built around two 50-mm lenses (Rodenstock) that imaged the optical fiber outputs onto the sensor of a fast CMOS camera (sensor area: 10 × 10 mm; frame rates ≤10 kHz; MiCAM Ultima, SciMedia, USA).

Techniques: Derivative Assay