B6 129s gt rosa 26sortm32 cag cop4 h134r eyfp hze j

We used C57BL/6 male mice unless otherwise noted (at least 8 weeks old). In addition, we used several genetically modified mouse lines (Camk2, Rbp4, Thy1, Rbp4-Ai32, and Pv-CRE): (B6.Cg-Tg(Camk2a-cre)T29-1Stl/J from the Jackson Laboratory, Tg(Rbp4-cre) from the Jackson Laboratory, B6.Cg-Tg(Thy1-COP4/EYFP)18Gfng/J from the Jackson Laboratory, B6;129S-Gt(ROSA)26Sortm32(CAG-COP4*H134R/EYFP)Hze/J from the Jackson Laboratory crossed with RBP4 mice as above, and B6;129P2-Pvalbtm1(cre)Arbr/J from the Jackson Laboratory. The Hebrew University Animal Care and Use Committee approved all experiments (IACUC NS-16-14216-3, “Functional identification of brain regions involved in ultrasonic vocalization in mice.”).

All experiments followed guidelines of the European Union for the care and use of laboratory animals (Council directive 86/609EC) and were approved by the ethics committee of the University of Paris Descartes (registered numbers CEEA34.EA.027.11 and CEEA16-032). C57BL/6 wild-type and transgenic male and female mice were used for the experiments. Cx30-CreERT2^{+/− 
31 (link)} mice were crossed with hetero- or homozygous Ai32 mice (B6;129S-Gt(ROSA)26Sor^{tm32(CAG-COP4*H134R/EYFP)Hze}/J, Jackson Labs). These Ai32 mice carry the ChR2(H134R)–EYFP gene in their Gt(ROSA)26Sor locus^{80 (link)}. CreERT2–mediated induction of ChR2 expression was induced by a single intraperitoneal injection of 1 mg 4-hydroxytamoxifen per approximately 8 g mice weight (Santa Cruz, sc-3542A) around postnatal day 21 (P21). Mice were analyzed at least two weeks after tamoxifen injections.

All animal handling and experimentation were performed according to the guidelines laid by the UK Home Office and Animals (Scientific Procedures) Act of 1986 and approved by the Newcastle University Animal Welfare and Ethical Review Body (AWERB #545). Cortical channelrhodopsin-2 (ChR2) expression was achieved by using genetically engineered transgenic mice. Brain slices were prepared from first-generation cross-breeding of homozygous floxed channelrhodopsin mice (B6; 129S-Gt(ROSA)26Sortm32(CAG-COP4*H134R/EYFP)Hze/J; stock #012569, The Jackson Laboratory) with homozygous PV-cre mice [B6; 129P2-Pvalbtm1(cre)Arbr/J; stock #008069, The Jackson Laboratory].

All experiments were performed according to the guidelines of the Stockholm municipal committee for animal experiments under an ethical permit to G.S. (N2022-2020). Mice (N = 82) of both sexes between 2 and 3 months of age were housed in groups from two to five in polycarbonate individually ventilated cages equipped with environmental enrichment (carton tubes and wood sticks). The cages were kept under constant temperature and humidity with a 12 h light/dark cycle and ad libitum access to food and water. D1-Cre (B6.FVB(Cg)-Tg(Drd1-cre)EY217Gsat/Mmucd, GENSAT, MMRRC_034258-UCD), D2-Cre (STOCK Tg(Drd2-cre)ER44Gsat/Mmucd, GENSAT, MMRRC_017263-UCD) or Adora2a-Cre (STOCK Tg(Adora2a-cre)KG139Gsat/Mmucd, GENSAT, MMRRC_031168-UCD) mice were crossed with the Channelrhodopsin (ChR2)-YFP reporter mouse lines (B6;129S-Gt(ROSA)26Sortm32(CAG-COP4*H134R/EYFP)Hze/J, the Jackson Laboratory, IMSR_JAX:012569) to induce expression of ChR2 in either dMSNs or iMSNs.

All experimental procedures were carried out in accordance with institutional animal welfare guidelines and licensed by the Veterinary Office of the Canton of Basel, Switzerland or under the UK Animals (Scientific Procedures) Act of 1986 (PPL 70/8116) following local ethical approval. For this study we used 35 male C57BL6 mice (supplied by Janvier labs) and 10 mice (7 males, 3 females) from a transgenic cross between B6;129S-Gt(ROSA)26Sortm32(CAG-COP4^∗H134R/EYFP)Hze/J and B6.129-Tg(Pcp2-cre)2Mpin/J lines (The Jackson Laboratory) aged > 60 days postnatal.