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Fig. 5
Spontaneous Activity Correlations between Newborn and Functionally Mature Tectal Neurons
(A) Top: examples of optical planes of the optic tectum at 1–4 dpe (5–8 dpf). Neurons are color coded according to their pairwise correlation values (color scale bar) with the newborn neuron (red neuron). The scale bars represent 50 μm. Bottom: zoomed image of the dashed areas on top. The scale bars represent 20 μm. Neurons involving few pixels (less than five) or with unstable baselines (rapid changes generally indicating movement artifacts) were left unlabeled. L, left; R, right; A, anterior; P, posterior.
(B) Probability density for the correlations between the newborn-labeled and the functionally mature neurons. Black, the pairwise correlations; blue, the corresponding null model. The null model was used to determine significant correlations (threshold: p < 0.01; dashed green line).
(C) The developmental dynamics of the relationship between the percentage of significant correlations and the physical distance between the neurons for the newborn-labeled neurons (red) and the functionally mature neurons (blue) from 1 to 4 dpe. Confidence intervals show SEM. Gray shaded areas indicate significant differences between newborn and functionally mature curves (p < 0.01; Mann-Whitney U test).
(D) The developmental dynamics of the average of the significant correlations between newborn-labeled neurons and the rest of the tectal neurons (red) and the significant correlations between the functionally mature neurons (blue). ∗p < 0.05; ∗∗p < 0.01. The error bars represent SEM.
(E) Left: example of the same newborn-labeled neuron chronically imaged at 2, 3, 4, and 10 dpe. Tectal neurons are color coded according to their pairwise correlation values with the newborn-labeled neuron (red). The scale bars represent 50 μm. Note their displacement away from the unlabeled neurogenesis region. Insets represent the morphology of the labeled neuron. The scale bar represents 20 μm. Right: relationship between the significant correlations between the newborn-labeled neuron with the rest of the imaged tectal neurons and the physical distance between the neurons for each imaged developmental stage (2, 3, 4, and 10 dpe).
(F) Top: developmental dynamics of the incorporation of newborn-labeled neurons into neuronal tectal assemblies. The tectal neurons are color coded according to the assembly they belong to (the position of the assembly along the caudo-rostral tectal axis). The newborn-labeled neuron is colored in magenta. The scale bars represent 50 μm. Bottom: zoom of the dashed areas in the top panel. The newborn-labeled neuron is circled in magenta. Note that, only at 3 dpe, the newborn-labeled neuron is also colored in blue, indicating that it is part of one of the assemblies. Neurons involving few pixels (less than five) or with unstable baselines (rapid changes generally indicating movement artifacts) were left unlabeled. The scale bars represent 20 μm.
(G) Probability of incorporation of newborn-labeled neurons into the neuronal assemblies (red) and the probability of the functionally mature neurons to belong to one of the neuronal assemblies (blue) for 1–4 dpe (newborn neurons: n = 6, 15, 21, and 15; functionally mature neurons: n = 1,962, 3,564, 5,296, and 3,969 from 6, 10, 17, and 11 larvae, respectively). ∗p < 0.05; ∗∗∗p < 0.001. The error bars represent SEM.
See also Figure S3.