a, Features of genomic loci interacting with promoters in the adult cerebellum. MAPS analyses of PLAC-seq data identified promoter-centric interactions enriched for regulatory regions of the genome marked by occupancy of CTCF or H3K27ac. b, c, PLAC-seq analyses of the number of home-specific and opto-specific interactions (b, P = 4.7 × 10−5, chi-square test, n = 2 biological replicates) or changes in interaction frequency (c, **P = 0.0045, ***P = 0.00026, two-sided Wilcoxon signed rank test, n = 83, 49 enhancer–promoter pairs for FC > 0.585, FC < −0.585) between promoters and enhancers harbouring upregulated (blue, fold change >0.585 or >1, log 2 ) or downregulated (green, fold change <−0.585, log 2 ) H3K27ac levels upon optostimulation of granule neurons. Box plots show median, quartiles (box) and range (whiskers). d, Features of frequently interacting regions (FIREs) in the adult cerebellum. e, The number of home-specific and opto-specific FIREs within 200 kb of TSSs harbouring upregulated (blue, fold change >0.585 or >1, log 2 ) or downregulated (green, fold change <−0.585, log 2 ) H3K27ac levels upon optostimulation of granule neurons (P = 8.8 × 10−7, chi-square test, n = 3 biological replicates). f, The profile of H3K27ac surrounding the distal (left) or proximal (right) enhancers of genes indicated in Fig. 4d (n = 2 biological replicates). Data show mean. g, h, A representative image of a granule neuron labelled with DNA FISH probes targeting the Nr4a3 (green) or Gapdh (red) gene together with Hoechst (g, n = 416 nuclei). The dotted line indicates the nucleus. The co-localization of the Nr4a3 and Gapdh genes upon optostimulation (h, n = 2 mice). Data show mean. i, Bins along chromosomes upon optostimulation of granule neurons (n = 24,046 bins). The Pearson correlation coefficient (corr) is shown. j, PLAC-seq analyses of inter-chromosomal normalized interaction frequency between genomic loci at 100 kb resolution harbouring upregulated (blue, fold change >0.585, log 2 ) or downregulated (green, fold change <−0.585, log 2 ) H3K27ac levels as in Fig. 4j. k, Sagittal sections from the cerebellum of Cas9-EGFP-GC mice infected with AAV9-gRNA-mCherry as in Fig. 5f and subjected to immunohistochemistry using the GFP and DsRed antibodies and DAPI (n = 4 mice). Scale bar, 100 µm. l, The ADCV of conditional CRISPR Rad21-knockout or control mice analysed as in Fig. 5j (n = 2, 2, 5, 5 mice for home-control, home-Rad21-cKO, US + CS control, US + CS Rad21-cKO). Data show mean and error bars denote s.e.m.