Figure 7. Manipulating neural ensembles with high temporal and spatial precision.
a) Top, schematic of all-optical ensemble experiments as in (Fig 5). 33 ensembles of 10, 25, or 50 neurons are stimulated with 10 pulses at 10–30 Hz. Bottom, representative images of 3 plane FOV (550 × 550 × 100 μm), depth from pial surface noted. Inset, enlargement showing example calcium source expressing ST-ChroME.
b) A representative neuron stimulated as part of five different ensembles composed of varying numbers of cells. Top, normalized mean dF/F (black) or OASIS deconvolution (red) during stimulation. Bottom, raster plots showing z-scored deconvolved calcium activity from 10 stimulation trials (top) or control trials (bottom).
c) Summary data from experiments in three mice. Each point represents the mean change in z-scored calcium response of all ensemble members in response to stimulation of the target ensemble (red) or mean response to stimulation of other ensembles (gray). Ensembles significantly increased their fluorescence only when they were stimulated (*** indicates p<0.001. Mouse 1: n = 33 ensembles, p=3.5×10−10, Mouse 2: n = 22 ensembles, p=2.8×10−4, Mouse 3: n = 24 ensembles, p=5.5×10−4, paired two-sided t-test).
d) Normalized z-scored calcium response of the neurons that compose each stimulated ensemble upon stimulation of each ensemble. Color codes show the size of the ensembles (green: 10, brown: 25, blue: 50 neurons).
e–g) Responses of each neuron in each ensemble to each ensemble stimulation, grouped by ensemble identity and separated by size. Scalebars are shared between e–g. Data represent the mean z-scored deconvolved calcium response for each neuron.
h) Maps showing the mean response of all calcium sources to stimulation of four unique ensembles composed of 50 cells across 3 depths. Green asterisks indicate neurons that were targeted for stimulation. Note: ensembles can be distributed in 3D (ensemble 1) or confined to one depth (ensembles 2–4). Data calculated from 0–300 ms after stimulation.