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Fig. 5 Morris water maze tank
(indication of memory function). The last trial consists of
placing the rat in the east direction, with a visible platform
(plexiglass circle with white surface and darker sides is placed
above the platform so as to bring it above the surface of water).
This trial helps to find the time the rat takes to find the plat-
form (assesses the visual function). The tank is cleaned once in
a week. The water level is checked every day and kept constant
throughout the trials. The water surface is kept clean with min-
now nets after each trial (see Note 13).
3.4 Tissue
Preservation
1. Animal sacrifice: The animals are deeply anesthetized and intu-
bated as described above. After intubation the rest of the pro-
cedure is carried out inside a chemical fume hood. A midline
incision is made over the abdomen and extended upwards and
towards both sides of the chest in shape of “V.” Once the infe-
rior surface of diaphragm is seen it is cut close towards the
chest wall to enter into the thoracic cavity. The beating heart is
visualized. The left ventricle is then pierced with an 18 G can-
nula (rats) or a 21 G cannula (mice) and 0.9% saline is perfused.
The right atrium is opened with a scissors and the animal is
exsanguinated. When the returns from the right atrium are clear,
4% paraformaldehyde is perfused (about 200-250 ml for rats
and 50-75 ml for mice). If the brain vessels are well perfused
then the animal will have tonic posturing with diffuse muscle
twitching. Then the animal is decapitated using a guillotine.
Skull is exposed. Working from the foramen magnum upwards,
using a small bone rongeurs, the cranial bones are slowly
removed in progressive bites. Once the cranial vault is removed
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