2. Methods
All animal care and experimental procedures were reviewed and approved by the institutional animal welfare and ethical review body (AWERB) at the University of Warwick or in accordance with the National Institutes of Health Guidelines for the Use of Animals. Experiments were performed under the appropriate project licenses with local and national ethical approval. Animals were kept in standard housing with littermates, provided with food and water ad libitum and maintained on a 12:12 (light-dark) cycle. The ArcKR knock-in mice were originally produced by the Ingenious Targeting Laboratory (Ronkonkoma, NY). Gene targeting was performed in iTL IC1 (C57BL/6) ES cells to introduce 2-point mutations within Exon 1 of the Arc gene that when encoded substitutes lysine to arginine at positions 268 and 269 (Wall et al. , 2018).