Fig. 6

Fig. 6

Noradrenergic System Activates Radial Astrocytes and Is Required for Futility-Induced Passivity

(A) Rate of neuronal activity increase before passivity onset quantified by the exponent of an exponential fit to average Ca²⁺ signals before passivity (overlay of 5 fish, Tg(elavl3:GCaMP6f)). Population with the highest rate of increase overlaps with NE neurons (see Figure S6A).

(B) Simultaneous imaging of NE neurons and radial astrocytes. Example Ca²⁺ signals just before, at, and after passivity onset.

(C) Examples of NE-MO activity, glial Ca²⁺ increases, and swimming in an alternating closed- and open-loop protocol. Right: average Ca²⁺activity from NE-MO and radial astrocytes, aligned to NE-MO response onset, radial astrocyte response, or passivity onset.

(D) Experimental design: single-cell 2-photon ablation of LC, NE-MO, or DRN in transgenic zebrafish labeling these nuclei.

(E) Time in passivity was strongly reduced after NE-MO ablation, but not after ablation of LC or DRN. Two-tailed paired t test, p = 0.95, n = 10 fish for LC; p = 0.40, n = 6 fish for DRN; p = 0.0070, n = 5 fish for NE-MO.

(F) Example shows NE-MO ablation reduced futility-induced passivity. Arrows in (E), corresponding data points.

(G) Experimental design: optogenetic activation of NE-MO cells using DMD-targeted light delivery in fish expressing CoChR in NE cells while imaging radial astrocytes expressing jRGECO1b.

(H) Example fish, NE-MO activation led to increased L-MO glial Ca²⁺, then passivity. Swimming increases briefly at light onset (see Figure S6D).

(I) Population data: NE-MO activation increased L-MO glial Ca²⁺ (left) and reduced swimming (right) in CoChR⁺ fish. Two-tailed paired t test, CoChR⁺ imaging, p = 0.025, n = 5 fish; CoChR⁺ behavior, p = 0.0024, n = 6 fish; CoChR⁻ imaging, p = 0.52, n = 7 fish; CoChR⁻ behavior, p = 0.56, n = 5 fish; glial ablation, p = 0.27, n = 6 fish.

(J) Experiment to identify receptors. Experiment as in (G) with NE receptor antagonists added to bath.

(K) α1 NE receptor antagonist prazosin (50 μM) abolishes radial astrocyte response evoked by NE-MO stimulation.

(L) Population data. α1 NE receptor antagonist prazosin (50 μM) or α1B antagonist cyclazosin (10 μM) abolished radial astrocyte responses. Two-tailed paired t test, prazosin, p = 4.6 × 10⁻⁵, n = 9 fish; cyclazosin, p = 0.0042, n = 5 fish. Shading, SEM.

(M) Experimental design to test whether L-MO radial astrocytes integrate NE and local circuit activity. In closed loop, NE-MO cells are optogenetically stimulated during swimming (higher L-MO neuronal activity), or during not swimming.

(N) Integration of NE and local circuit activity. Radial astrocytic Ca²⁺responses to NE during swimming are larger than to NE alone. Left: examples from successive trials. Right: summary of all fish. Two-tailed paired t test, p = 2.4 × 10⁻⁴ for NE-MO stimulation only versus swimming only, p = 2.4 × 10⁻⁸ for NE-MO stimulation + swimming versus swimming only, n = 12 fish. Shading, SEM.