Removing direct photocurrent artifacts in optogenetic connectivity mapping data via constrained matrix factorization
Fig 4
Validating photocurrent subtraction with synaptic transmission block.
a, We used the grid design to map synaptic connections in a two part experiment. During the control block, we recorded photocurrents along with synaptic currents as in prior experiments. b, Raw and subtracted traces from two ROIs during the control block. ROI 1 is far from the putative location of the postsynaptic cell, while ROI 2 is nearby. c, Raw and subtracted grid maps from the control block. The colorbar for the “control raw” map has been truncated to improve legibility. ROIs correspond to the traces shown in b. d, After bath application of NBQX, we repeated the mapping experiment on the same patched cell, recording isolated photocurrents. e, Raw and subtracted traces from the NBQX block for the same two ROIs as in b,c. As expected, nearly all currents are removed from ROI 2. f, Raw and subtracted grid maps from the NBQX block. As expected, the subtracted maps during the NBQX block appear blank. ROIs correspond to the traces shown in e.