Wildtype (WT) and knockout (KO) male mice were bred from heterozygous pairings and maintained on a mixed 50% C57BL/6J –50% 129SvEv background. α2-subunit KO mice were generated as previously described [19]. Animals were housed in pairs under a 12 hr light/dark cycle (lights on at 7.00 AM) in a holding room with controlled temperature (≈21°C) and humidity (≈50%). Except where specified, animals had ad libitum access to standard laboratory chow (Bekay Feeds, Hull, UK) and water within the home cage. Mean body weight at the start of the experiment was approximately 30 g.
