Flaxedil

Cats were initially sedated with a mixture of Acepromazine (Atravet, 0.1 mg/kg, s.c., Wyeth-Ayerst, Guelph, ON, Canada) and atropine sulphate (Isopto Atropine, 0.04 mg/kg, s.c., Atrosa; Rafter, Calgary, AB, Canada) followed by a dose of anesthetic ketamine (Narketan, 40 mg/kg, i.m.; Vetoquinol, QC, Canada). Anesthesia was maintained during the surgery with isoflurane ventilation (2%, AErrane; Baxter, Toronto, ON, Canada). After the surgery, cats were fixed on the stereotaxic and were paralyzed by perfusion of gallamine triethiodide (Flaxedil, 40 mg/kg, i.v.; Sigma Chemical, St Louis, MO, USA). Artificial ventilation was maintained by a mixture of O 2 /N 2 O (30:70) and isoflurane (0.5%). The paralysis was continued by perfusion of gallamine triethiodide (10 mg/kg/h) in 5% dextrose lactated Ringer's nutritive solution (i.v., Baxter, Mississauga, ON, Canada) throughout the experiment.

Animals premedicated with acepromazine maleate (Atravet, Wyeth-Ayerst, Guelph, ON, Canada; 1 mg/kg, intramuscular) and atropine sulphate (ATRO-SA, Rafter, Calgary, AB, Canada; 0.04 mg/kg, intramuscular) were anesthetized with ketamine hydrochloride (Rogarsetic, Pfizer, Kirkland, QC, Canada; 25 mg/kg, intramuscular). The cats were then paralyzed with 40 mg and maintained with 10 mg/kg/h of gallamine triethiodide (Flaxedil, Sigma Chemical, St. Louis, MO, USA; intravenous) administered in 5% dextrose lactated Ringer's nutritive solution. General anesthesia was maintained by artificial ventilation with a mixture of N2O/O2 (70:30) supplemented with 0.5% isoflurane (AErrane, Baxter, Toronto, ON, Canada).
Electroencephalogram, electrocardiogram, rectal temperature and end-tidal CO2 partial pressure were monitored throughout the experiment, and kept in physiological ranges. The pupils were dilated with atropine sulfate (1%, Isopto-Atropine; Alcon, Mississauga, Ontario, Canada) and the nictitating membranes were retracted with phenylephrine hydrochloride (2.5%, Mydfrin, Alcon). The loci of the area centrales were inferred from the position of the blind spots which were opthalmoscopically focused and projected onto a translucent screen. At the end of the experiment, the cats were euthanized intravenously with a dose (0.5 mL/kg) of Sodium Pentobarbital (CEVA, Sante Animale).