Blau, Axel
Coauthors(s): T. DeMarse J. Pine S. Potter Caltech, Div. of Biology
California Institute of Technology
Division of Biology
156-29 Pasadena, CA 91125
www.caltech.edu/~pinelab/PotterGroup.htm

High-speed imaging of neuronal network activity

To complement electrical recording techniques, a high-speed digital camera system based on a 4096 pixel CCD chip with sub frame readout times below one ms has been developed and applied to neuronal networks of dissociated cortical neurons of embryonic rats (E18) in vitro. Neurons cultured on microelectrode arrays (MEAs) for 3 to 5 weeks were stained with a fast-response potential-sensitive fluorescent dye (Di-8-ANEPPS). This allowed both optical recording with the high-speed camera and simultaneous electrical recording with a MEA to compare and correlate spontaneous as well as chemically altered activity patterns. While the high-speed camera can resolve signal spread and neuronal activity in the vicinity of a stimulation site in higher resolution compared to electrode arrays, photo bleaching of the dye limits its use to taking temporary snapshots of activity. The focus of the presentation will lie on the description of the approach and of the choice of parameters. In addition to preliminary results, spectral characteristics of various voltage-sensitive dyes bound to mainly cortical neurons in suspension and in culture are presented.