Fig. 5

Figures for Mu et al., 2019
Figure Caption

Fig. 5

Activation of Radial Astrocytes Reduces Swimming

(A) Experimental design. Rat TRPV1 was expressed in ∼1% of radial astrocytes in Tg(gfap:jRGECO1b) fish. Fish were exposed to the TRPV1 agonist capsaicin.

(B) Example fish with increased Ca2+ transients in L-MO and concurrent increase in passivity after capsaicin treatment. The effect diminished after ∼1 h, maybe due to TRPV1 desensitization and internalization (Sanz-Salvador et al., 2012), showing that fish remain healthy, as they can swim normally. Dashed line (passive) means the fish is passive 100% of the time; dashed line (active) means it is passive 0% of the time (both measured in 2 min bins).

(C) Population data, showing increased passivity after activation of TRPV1. n = 7 fish.

(D) Population data of L-MO astrocytic Ca2+ increase and passivity with TRPV1 activation. Two-tailed paired t test, behavior: p = 0.0029, n = 7 fish. ΔF/F: p = 0.027, n = 5 fish.

(E) Astrocytic Ca2+ in L-MO near passivity onset. Average signal increased just before passivity onset and peaked just after, as in futility-induced passivity (Figures 2G–2I). Shading, SEM.

(F) Control, example. No reduction of swimming or increase in astrocytic Ca2+ when saline was added to fish expressing TRPV1.

(G) Control, population data. No change in behavior when saline was added to fish expressing TRPV1 (n = 6 fish) or capsaicin to fish without TRPV1 (n = 5 fish).

(H) Summary of controls. Experiments as in (F) and (G) were pooled. Two-tailed paired t test, behavior: p = 0.48, n = 11 fish. ΔF/F: p = 0.51, n = 7 fish.

(I) Normalized mean L-MO glial Ca2+ signals centered on the onset of passivity, induced by TRPV1 in closed loop (top) or by motor futility in open loop (bottom). Surges appear similar. Ca2+ in TRPV1+ animals did not saturate.

(J) Experimental design. Local optogenetic excitation of glial processes in fish expressing CoChR or Opto-α1-AR increases glial Ca2+ in L-MO (CoChR shown).

(K) Optogenetic (CoChR) excitation of L-MO glia reduced swimming for ∼10 s. Blue light outside the brain caused a much milder and briefer reduction.

(L and M) Population data show reduced swimming relative to controls in fish expressing CoChR (L) or Opto-α1-AR (M) in radial astrocytes. Two-tailed paired t test, CoChR, p = 0.00012, n = 9 fish; Opto-α1-AR, p = 0.0065, n = 10 fish.

(N–P) Controls for (K)–(M) show no effect in fish without CoChR or Opto-α1-AR. Two-tailed paired t test, CoChR: p = 0.89, n = 6 fish. Opto-α1-AR, p = 0.50, n = 8 fish.

(Q) Summary of Figures 4 and 5, showing significant increases in passivity after increases in astrocytic Ca2+, decreases after astrocytic silencing, and no effects in control experiments. Effects are normalized by maximal possible change (control passive % for decreases; control active % for increases) for each fish.

(R) Optogenetic activation of L-MO radial astrocytes activates GABAergic neurons at edge of L-MO in Tg(gfap:CoChR-eGFP);Tg(elavl3:jRGECO1b) fish. Left: maximum-intensity projection of ΔF/F after optogenetic activation of radial astrocytes (magenta) and anatomy (cyan) in example fish. Inset: Ca2+ in GABAergic neurons after astrocytic activation; stimulation time in cyan. Top right: Tg(gad1b:RFP);Tg(elavl3:H2B-GCaMP6f) used to label GABAergic neurons; bottom right: Tg(gad1b:Gal4);Tg(UAS:CoChR-eGFP) to sparsely label GABAergic neurons.

(S) Activation of GABAergic cells with laser light in Tg(Gad1b:Gal4);Tg(UAS:CoChR-eGFP) suppresses swimming. Two-tailed paired t test, p = 0.0074, n = 7 fish.

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Reprinted from Cell, 178(1), Mu, Y., Bennett, D.V., Rubinov, M., Narayan, S., Yang, C.T., Tanimoto, M., Mensh, B.D., Looger, L.L., Ahrens, M.B., Glia Accumulate Evidence that Actions Are Futile and Suppress Unsuccessful Behavior, 27-43.e19, Copyright (2019) with permission from Elsevier. Full text @ Cell