B6 cg tg thy1 yfp hjrs j mice

Male B6.Cg-Tg(Thy1-YFP)HJrs/J mice (Jackson Laboratories, Bar Harbor, ME) between 8–10 weeks of age were used for all experiments. Mice were maintained in a 12 h dark/light cycle with access to food and water ad libitum. All procedures were performed in accordance to the guidelines of the National Institutes of Health and the Chancellor’s Animal Research Committee of the University of California, Los Angeles Office for the Protection of Research Subjects.

The behavioral data were collected from 7 adult (P90-P365) male mice whose genotypes are either (1) C57BL/6J [n = 2], (2) Slc6a3^{tm1.1(cre)Bkmn}/J [n = 2], or (3) B6.Cg-Tg(Slc32a1-COP4*H134R/EYFP)8Gfng/J [n = 3; called vGAT-ChR2 in this report]. The same set of vGAT-ChR2 mice were used for photoinhibition experiments. These mice were obtained from the Jackson Laboratory (see Resources Table). For the photo-bleaching assay (Figure S4), we used B6.Cg-Tg(Thy1-YFP)HJrs/J mice (n = 3, Jackson Laboratory). For the electrophysiological confirmation of inhibition (Figure S4), we used 5 additional vGAT-ChR2 mice. All mice were housed on a 12h dark/12h light cycle (dark from 06:00–18:00) and each performed the behavioral task at the same time of day, between 07:00 and 19:00. After surgery they were individually housed. All mice were maintained above 90% of their initial weight, and no mouse was given less than 1.5 mL water per day. All surgical and experimental procedures were in accordance with the National Institutes of Health Guide for the Care and Use of Laboratory Animals and approved by the Harvard Institutional Animal Care and Use Committee. A subset of mice (n = 2) in this study was first tested in a similar adaptation task (unpublished data) prior to participating in this study (but in no more than 8 sessions).