Fluorescent voltage-sensitive dye JPW-3028 was injected into layer V pyramidal neuron in the rat somatosensory cortex. Microphotographs capture the dendritic tree at different focal planes.
Same cell as above. The dendritic tree is now captured by the data acquisition camera during the actual voltage imaging sweep. Data acquisition camera is characterized by low resolution (80 x 80 pixels) but fast sampling rate (full frame per 0.37 milliseconds). The morphology of the living cell is projected onto the 80 x 80 array of optical detectors (pixels). By selecting a pixel from the array one can select the recording site. In this example, we chose one recording site near the soma (yellow), in the proximal basal dendrite (blue), in the distal basal dendrite (clay), at the oblique branch point (turquoise) and in the apical dendrite (red). Recordings are performed simultaneously from multiple locations, which provides a unique view in the signal initiation and propagation within the dendritic tree.
Action potential was triggered in the cell body. Action potential-associated optical signals are captured from five regions of interest marked by colored pixels in the left image. Each signal is a spatial average of several pixels, and temporal average of four consecutive sweeps.