Automatic segmentation of odor maps in the mouse olfactory bulb using regularized non-negative matrix factorization.
Segmentation of functional parts in image series of functional activity is a common problem in neuroscience. Here we apply regularized non-negative matrix factorization (rNMF) to extract glomeruli in intrinsic optical signal (IOS) images of the olfactory bulb. Regularization allows us to incorporate prior knowledge about the spatio-temporal characteristics of glomerular signals. We demonstrate how to identify suitable regularization parameters on a surrogate dataset. With appropriate regularization segmentation by rNMF is more resilient to noise and requires fewer observations than conventional spatial independent component analysis (sICA). We validate our approach in experimental data using anatomical outlines of glomeruli obtained by 2-photon imaging of resting synapto-pHluorin fluorescence. Taken together, we show that rNMF provides a straightforward method for problem tailored source separation that enables reliable automatic segmentation of functional neural images, with particular benefit in situations with low signal-to-noise ratio as in IOS imaging.
Neuroinformatics & Theoretical Neuroscience, Institute of Biology, Freie Universität Berlin, 14195 Berlin, Germany.
Jan
J
Soelter
Max-Planck Institute for Biophysics, Frankfurt am Main, Germany.
Jan
J
Schumacher
Max-Planck Institute for Biophysics, Frankfurt am Main, Germany.
Hartwig
H
Spors
Neuroinformatics & Theoretical Neuroscience, Institute of Biology, Freie Universität Berlin, 14195 Berlin, Germany; Bernstein Center for Computational Neuroscience Berlin, 10119 Berlin, Germany. Electronic address: m.schmuker@fu-berlin.de.
Michael
M
Schmuker
D000465:Algorithms; D000818:Animals; D001931:Brain Mapping / Q000379:methods*; D007091:Image Processing, Computer-Assisted; D051379:Mice; D009812:Odorants; D009830:Olfactory Bulb / Q000502:physiology*; D061848:Optical Imaging / Q000379:methods*; D012903:Smell / Q000502:physiology*
Independent component analysis; Intrinsic optical signal; Non-negative matrix factorization; Olfactory bulb