Morris Water Maze Experiment Lab Report

2.4. Animals
One hundred twelve adult male Wistar rats (Pasteur Institute, Tehran, Iran) weighing 220-250 g were housed in groups of four per cage in a controlled environment (temperature 23±1°C, 12h light/dark cycle) with free access to food. Rats were habituated to the new environment for seven days before the test. All experiments were performed in accordance with the guide for the care and use of laboratory animals (IR.SBMU.nrc.REC.1390.20) approved by the Research and
Ethics Committee of the Shahid Beheshti University of Medical Sciences. All efforts were made to diminish the number of animals and their suffering during the experiment.
2.4.1. Surgery and microinjection
For stereotaxic surgery, all the rats were anesthetized by intraperitoneal
All these groups were studied by two experimental protocols: molecular studies (n=4 rats/ group) seven days after Aβ-injection and behavioral experiments (n=10 rats/ group) nineteen days following Aβ-injection [19].
2.5. Behavioral test: Morris water maze (MVM)
2.5.1. Apparatus
The Morris water maze test was conducted as described
[20, 21]. The maze consisted of a circular pool (200 cm in diameter) filled with water (23±2°C) to a depth of 40cm. The circular pool divided into four arbitrary quadrants. A transparent
Plexiglas platform (the only escapable thing from the water) 10cm in diameter was submerged
2cm underneath the water surface at the midpoint of one quadrant. There were many distinct visual cues on the walls surrounding the pool. These particular cues remained in a fixed position with respect to the circular swimming pool during the test to allow the rat to locate the hidden platform. A camera that was located above the center of the swimming pool monitored the animal’s position. Movement of animal was recorded with a 3CCD camera (Panasonic Inc.,
Japan) which was placed 2m above the MVM apparatus. Ethovision software (Version XT7) a video tracking system for automation of behavioral tests (Noldus Information Technology,
The basis of this technique is the spectrophotometric measurement of the purple color produced via the reaction of thiobarbituric acid (TBA) and MDA. Concisely, half a milliliter of hippocampal homogenate was mixed with
2.5 ml of trichloroacetic acid (TCA) (10% w/v) solution and the mixture was boiled in a water bath for 15 min. The samples were cooled to room temperature and the absorbance at 532 nm was measured with respect to the blank solution.

2.9. Superoxide dismutase activity assay
SOD activity was measured based on the extent of inhibition of amino blue tetrazolium formazan formation in the mixture of nicotinamide adenine dinucleotide (NADH), phenazine methosulfate
(PMS) and nitroblue tetrazolium (NBT) as described previously[26]. Concisely 0.1 ml of supernatant, 1.2 ml of sodium pyrophosphate buffer (pH8.3, 52 mM), 0.1 ml of phenazine methosulfate (186 μM), 0.3 ml of nitro blue tetrazolium (300 μM) and 0.2 ml of NADH (750 μM) were mixed together. The reaction started by addition of 0.2 ml of NADH. After incubation at 30 ̊C for90s, the reaction stopped by the addition of 0.1ml of glacial acetic acid.
2.10. Catalase activity assay
Abei’s method [27]was used for Measurement of Catalase activity. 5μl of tissue lysis was