Histopathological Assessments of Animal Models of Cerebral Ischemia - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 4

2.2. Anesthesia Agent

Isofl urane and halothane are commonly used to anesthetize animals
during surgical procedures of the perfusion. An inhalable anesthesia
agent is recommended in preparing histological tissue sections
because animal respiration can be mechanically controlled with a
ventilator to reduce tissue hypoxia during the perfusion-fi xation
procedure. In some situations, other anesthesia agents such as ketamine
or barbiturates can also be used to anesthetize animals for perfusion-
fi xation of tissues if tissue hypoxia is not a major concern.

2.3. Chemicals

Forty percent formaldehyde (Richard-Allen Scientifi c, Kalamazoo,
MI, USA); glacial acetic acid (Richard-Allen Scientifi c, Kalamazoo, MI,
USA); methanol (Richard-Allen Scientifi c, Kalamazoo, MI, USA);
saline; ethanol grades-100, 95, 80, and 70% (Richard-Allen
Scientifi c, Kalamazoo, MI, USA; Cat # 6201; 6301; 6401; 6501);
Gill hametoxylin (Surgipath, Richmond, IL, USA; Cat # 01500);
eosin Y (Surgipath, Richmond, IL, USA; Cat # 01602); citrus fruit
oil (Richard-Allen Scientifi c, Kalamazoo, MI, USA); paraffi n wax
(Richard-Allen Scientifi c, Kalamazoo, MI, USA).

These include a pair of curved forceps (Roboze Surgical Instrument
Company, Maryland, USA; Cat # RS-8254), operating scissors
(Roboze; Cat # RS-6951), a pair of microdissecting forceps
(Roboze; Cat # RS-5244), and a fi ne clamp (Fine Science Tools,
373-G Vintage Park Drive, Foster City, CA, USA; Cat # 18374-43),
syringes (1 ml and 10 ml; BD Biosciences, 2350 Qume Drive, San
Jose, CA 95131, USA), syringe adaptors (23 and 20 gauge; BD
Biosciences), intubation tube of 14GA, 1.75 in., 2.1 × 45 mm (BD
biosciences; Cat # 381467), polyethylene tubing (PE-50, BD Bio-
sciences), heparinized capillaries (Radiometer Copenhagen, Cat #
D941G-240-85), silastic tubing (inner diameter 0.76 mm and
outer diameter 1.65 mm; Dow Corning Corporation, Midland,
MI, USA), slides (VWR; Cat # 48311-703), hair brush (Ted Pella,
Redding, CA, USA; Cat # 11856), Parmount mounting medium
(Fisher Scientifi c, Pittsburgh, PA, USA; Cat # SP 15-50), pencil/
Securlin marker II—superfrost—permanent solvent-resistant (Precision
Dynamics Corporation, San Fernando, CA, USA; Cat # 1451).

2.4. Surgery
Instruments
and Supplies

3. Histological
Procedure

3.1. Perfusion-Fixation
of Animal Tissue

After desired experimental condition is met following an episode
of cerebral ischemia or brain injury, the rat is anesthetized in an
anesthesia box supplied with 4% isofl urane in 70% NO/30% O 2 ,
intubated through a tracheotomy and ventilated with 2% isofl urane
in 70% NO/O 2 . The rat chest case is opened surgically, and a cath-
eter is inserted via a 30-mm barrel (Cat # 18060-20; Fine Science
Tools, Foster City, CA) into the ascending aorta through the left