Figure 5.
Functional Brain-wide Neuronal Response to Dynamic Vestibular Step Stimulation, Paralyzed Fish
(A) Scatterplot showing the responsiveness of neurons to a step stimulus (correlation coefficient) versus the responsiveness to a sinusoidal stimulus (response amplitude is defined as the signal-to-noise ratio measured at the stimulation frequency; STAR Methods). Points are colored according to the phase shift of the response with respect to the sinusoidal stimulation. SNR, signal-to-noise ratio.
(B) Scatterplot of all neurons (same as A), with the correlation coefficient ρ as radius and the phase as angle, using the same color code as (A). The left panel shows all points with a positive ρ, whereas the right panel shows all points with a negative ρ (radius is the absolute value of ρ). Black contour lines indicate isovalues for the density distribution.
(C) Multi-regression analysis reveals three neuronal response clusters. Scatterplots of the regression coefficients (left column) and corresponding T scores (right column). Data are from the example fish shown in Video S5 and (A)–(E) and represent a total of 77,648 neurons. Neurons that do not belong to the responsive clusters are shown as gray dots; clustered neurons are colored according to the corresponding cluster color. The magenta cluster corresponds to neurons that display strong response to both positive angle and positive angular velocity (>95th percentile in both regression coefficient and associated T score). Neurons of the pale green cluster are highly responsive to both negative angle and negative angular velocity, whereas neurons from the golden cluster show high response to both positive and negative angular velocity.
(D) Top: trial-averaged traces of all neurons in the three clusters to stepwise stimulation. Neuron index is denoted on the left (1–1,168), ΔF/F scale color bar is shown at the top (values are clipped to [0, 0.5]), and neuron cluster assignment is shown in the color bar on the left. Neurons are grouped by cluster and subsequently sorted by coefficient strength to the position regressor, to show the gradient in response strengths. Bottom: rotation angle α of the vestibular step stimulus (black) and the trial- and neuron-averaged traces of the three clusters in their respective colors. Additionally, their mean regression fit is plotted (black filled line), and for the magenta cluster and pale green cluster the mean position-only fit is plotted (black dashed line) to illustrate the contribution of each regressor.
(E) Visualization of the cluster spatial organization performed for the same example fish with the Fishualizer. These data are also shown in Video S5, part II in 3D.
(F) The histogram shows for selected brain regions the fraction of neurons that are part of the three identified average cluster densities. Tel, telencephalon; Hab, habenula; PT, pretectum; DTh, dorsal thalamus; VTh, ventral thalamus; OT, optic tectum; TSC, torus semicircularis; Teg, tegmentum; TL, torus longitudinalis; Cer, cerebellum; Rh 1–7, rhombomere 1–7.
(G) Visualization of the average density map of N = 8 paralyzed fish with eyes. 3D visualization is in Video S5, part III. Color intensity scales linearly with density. Outlines of the indicated brain regions from rostral to caudal: habenula, torus longitudinalis, tegmentum, optic tectum, nMLF, oculomotor nucleus nIII, trochlear motor nucleus nIV, cerebellum, and inferior olive.
(H) Average density map of N = 11 bi-enucleated fish.
All data were recorded in Tg(elavl3:H2B-GCaMP6s) fish. Scale bars, 50 μm. See also Figure S5 and Video S5.