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Gatsby Computational Neuroscience Unit
Alexandra House, 17 Queen Square, LONDON, WC1N 3AR, UK
Tel: +44 (0) 20 7679 1176, Fax +44 (0) 20 7679 1173, admin@gatsby.ucl.ac.uk, www.gatsby.ucl.ac.uk

 

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WORKSHOP ON:
CENTRAL PROBLEMS IN SINGLE CELL COMPUTATION

16-18 September 2002
By invitation only

Venue
B10 Seminar Room, Alexandra House, 17 Queen Square, London, WC1N 3AR

Directionally selective calcium signals in dendrites of starburst amacrine cells
Winfried Denk, Max-Planck Institute for Medical Research, Department of Biomedical Optics, Heidelberg, Germany
The detection of image motion is fundamental to vision. In many species unique classes of retinal ganglion cells selectively respond to visual stimuli that move in specific directions. It is not known which retinal cell first performs the neural computations that give rise to directional selectivity in the ganglion cell. A prominent candidate has been an interneuron called the "starburst amacrine cell". Using 2-photon optical recordings of intracellular calcium concentration, we find that individual dendritic branches of starburst cells act as independent computation modules. Dendritic calcium signals, but not somatic membrane voltage, are directionally selective for stimuli that move centrifugally from the cell soma. This demonstrates that direction selectivity is computed locally in dendritic branches at a stage prior to ganglion cells.