Extended Data Fig. 4|. CCR5 activation measured with the CCR5-iTango2 system in vivo.

a-c, Validation of the leakage in CCR5-iTango2 system in vivo.

a, Schematics to test the CCR5-iTango2 system without light activation.

b, Representative images of EGFP and CCR5-iTango2-expressing dCA1 neurons after fear conditioning. Scale bar, 50 μm.

c, Quantification of EGFP expression (intensity normalized to tdTomato, n=3 mice per group).

d-f, Validation of the maraviroc mediated CCR5 inhibition in vivo.

d, Maraviroc was co-infused with CCL5 into mouse dCA1. The CCR5-iTango2 was used to measure CCR5 activation in vivo.

e, Representative images of CCR5-iTango2-expressing dCA1 neurons after fear conditioning. Scale bar, 50 μm.

f, Quantification of EGFP expression in different treatment (CCL5⁻Maraviroc⁻ n=3, CCL5⁺Maraviroc⁻ n=4, CCL5⁺Maraviroc⁺ n=3 mice; *P < 0.05, one-way ANOVA).

g-i, Analyses of colocalization of c-Fos and CCR5 activation in vivo.

g, Schematics to test c-Fos expression in EGFP⁺ cells after learning with the CCR5-iTango2 system.

h, Representative images of colocalization between EGFP and c-Fos in dCA1. Red arrows: c-Fos⁺EGFP⁺ cells. Scale bar, 50 μm.

i, Percentage of c-Fos⁺EGFP⁺ cells in total cells (6 h n=6, 12 h n=4, 24 h n=5 mice; *P < 0.05, two-way repeated measures ANOVA).

All results shown as mean ± s.e.m.