Terazosin

Following surgery, terazosin (Tocris #1506, Minneapolis, MN) prepared in DMSO was delivered through ad lib access to treated water. Water for control mice was made with equivalent volumes of DMSO alone. Preparation of terazosin began with a 100 mM stock solution (42 mg/ml in DMSO) stored at −80 °C. The stock was diluted 1:100 to make a 1 mM (0.42 μg/μl in water) working solution. We added 106 μl of working solution, equating to 45 μg terazosin (0.42 μg/μl × 106 μl), to 300 ml water, to which mice had free access. The concentration of the final drinking water was 0.15 μg/ml terazosin (45 μg/300 ml). An average mouse drinks approximately 5 ml of water per day^{27 (link)}, so each mouse consumed ~0.75 μg terazosin daily (0.15 μg/ml × 5 ml/day). Additionally, experimental mice weigh on average 0.025 kg^{27 (link)}; thus, the terazosin dose received by our animals was ~0.03 mg/kg/day (0.75 μg/0.025 kg/day). All terazosin- and DMSO-treated water was replaced every 2 days for the duration of the experiment post-surgery^{4 (link)}.

All standard chemicals were purchased from Sigma-Aldrich unless mentioned otherwise. CNQX (6-cyano-7-nitro-quinoxaline-2,3-dione, Sigma), clozapine-N-oxide (CNO) (Enzo Life Sciences), APV (D-2-amino-5-phosphono-pentanoic acid, Sigma), MPEP (6-(phenylethynyl)-pyridine, Tocris), terazosin (Tocris), metoprolol (Tocris), SN-6 (2-[4-(4-nitrobenzyloxy)benzyl]thiazolidine-4-carboxylic acid ethyl ester, Tocris), SEA0400 (2-[4-[(2,5-difluorophenyl)methoxy]-phenoxy]-5-ethoxyaniline, CM-4620 (Tocris), synthesized by Taisyo Pharmaceutical Co. Ltd), UTP (uridine 5’-triphosphate, Tocris).

In electrophysiological experiments, l-noradrenaline bitartrate monohydrate (NA; Tokyo Chemical Industry, Tokyo, Japan), CNQX (Alomone Labs, Jerusalem, Israel), dl-AP-5 (AP-5; Tocris Bioscience, Bristol, UK), terazosin hydrochloride (Sigma, St. Louis, MO, USA), atipamezole hydrochloride (Wako, Osaka, Japan), timolol maleate (Sigma), and phenylephrine hydrochloride (Wako) were dissolved in distilled water. Picrotoxin (Sigma) was dissolved in dimethyl sulfoxide. These drug solutions were diluted with standard Ringer’s solution before use. Kynurenic acid hydrate (KYNA; Tokyo Chemical Industry) was dissolved in standard Ringer’s solution. In behavioral experiments, Picrotoxin, NA, and terazosin (Tocris) were dissolved in phosphate-buffered saline (PBS). Picrotoxin injection into the cortex has been reported to elicit seizures^{29 (link)}. The doses of drugs were chosen based on the previous studies^{26 (link),30 (link)–32 (link)}.