Figure 8.

Gap Junctions Play a Role in Maintaining Criticality in the Nervous System

(A) Average distribution exponents (α, τ, σνz) of spontaneous neuronal avalanches displayed by larvae in normal experimental conditions (datasets 1–6; black bars) and by larvae exposed to heptanol (90 μM) (datasets 7 and 8; white bars). For comparison, the gray bars indicate the critical exponents of 3D random field Ising theoretical models.

(B and C) Profile (B) and recurrence-time (C) collapse indices of neuronal avalanches calculated in normal conditions (black bars) and under heptanol exposure (white bars). In (A)–(C), p indicates the p value of two-sample t tests; ^∗p < 0.05, ^∗∗p < 0.01. Error bars, SEM.

(D) Decoding of visual stimuli at one optical plane of the optic tectum (n = 14 larvae, 8 in normal conditions and 6 after expsure to heptanol at 90 μM). Stimuli consisted of single light spots randomly presented at 4 possible closely spaced azimuth locations in the visual field (75°, 85°, 90°, and 110°). A maximum likelihood decoder was used to classify the stimuli location based on the activity of n ROIs. For n > 100, the classification performance was significantly higher than chance (i.e., 25%) for larvae in normal conditions. However, the decoding efficiency was significantly lower for larvae exposed to heptanol. ^∗p < 0.001, two-sample t test.

(E) Decoding confusion matrices averaged across larvae in normal conditions (left) and across larvae exposed to heptanol (right), for n = 1,000. The off-diagonal matrix elements represent the probability of erroneously classifying one stimulus as a different one. The diagonal corresponds to correct classifications. Notice that, as expected, the decoder confused nearby stimuli.

See also Figure S8.