INTRODUCTION: ALZHEIMER IS A PROGRESSIVE DEMENTIA DISEASE ALONG WITH DESTRUCTION OF BRAIN NEURONS AND SEVERE DEFICIENCY OF MEMORY. FOR MANY YEARS PLENTY EFFORTS ARE DEVOTED TO FIND AN APPROPRIATE AND EFFICIENT WAY FOR TREATMENT OF THE DISEASE. THE PRESENT WORK WAS DESIGNED TO ASSESS THE EFFECT OF THE MAZE TRAINING IN IMPROVEMENT OF LEARNING BEHAVIOR OF THE ALZHEIMERIC RATS.METHODS: THIS EXPERIMENTAL STUDY WAS CARRIED OUT ON 20 WISTAR MALE RATS RANDOMLY DIVIDED IN 2 GROUPS. ONE GROUP THAT RECEIVING A DOSE OF BETA-AMYLOID INTRAVENTRICULRLY CHARACTERIZED AS ALZHEIMERIC RATS (ALZ). IN THE CONTROL GROUP (CO) THE ANIMALS WERE INJECTED SALINE AT THE SAME VOLUME. TO ASSESS SPATIAL LEARNING OF THE ANIMALS IN THE FIRST PHASE OF THE EXPERIMENT THEY WERE INTRODUCED TO THE MORRIS WATER MAZE TO LOCATE ON FIXED HIDDEN PLATFORM DURING 4 TRIALS/ DAY FOR 5 DAYS. PROBE TEST WAS APPLIED TO EVALUATE THE MEMORY RETRIEVAL. IN THE SECOND PHASE THE SAME PROCEDURE WAS REPEATED AFTER 20 DAYS. THE TWO IMPORTANT PARAMETERS INCLUDING TIME ELAPSED AND DISTANCE PASSED IN THE WATER MAZE DURING THE FIRST AND THE SECOND PHASES OF THE EXPERIMENT, WERE ANALYZED BY REPEATED MEASURE ANOVA.RESULTS: OUR FINDINGS INDICATE THAT IN THE FIRST PHASE OF EXPERIMENT, THE TIME ELAPSED AND DISTANCE PASSED FOR THE CO GROUP IS DECREASE COMPARED TO THE ALZ GROUP. IN THE SECOND PHASE, HOWEVER, SIGNIFICANT VARIATION WAS OBSERVABLE BETWEEN THE TWO TESTED GROUPS. THERE WAS NO SIGNIFICANT DIFFERENCE BETWEEN THE PERFORMANCE OF THE CO AND ALZ GROUPS IN PROBE TRIAL TESTING.CONCLUSION: IT SEEMS THAT THE BEHAVIORAL TRAINING POSITIVELY INFLUENCED THE MAZE LEARNING IN THE ALZ SUBJECTS SO THAT HOWEVER BOTH GROUPS BEHAVED SIMILARLY IN THE SECOND PHASE OF THE EXPERIMENT.

Spatial memory is responsible for recording of information about one's environment and its spatial orientation. In animals, spatial memory is needed to learn the location of food in field orat the end of a MAZE. In general, mammals require a functioning hippocampus in order to form and process memories about space. Despite Nandrolone side effects it has positive effects such as muscle growth, appetite stimulation, increasing erythrocytes and bone density. It uses for therapeutics or sport doping. This study was designed to evaluate the effect of intra-hippocampal injection of Nandrolone on radial MAZE spatial memory in rat.Male Wistar rats (n=4) were trained in two block each day. Each session included 10 trials, 5 min duration and 1 min intertribal. Animals were trained until they reached to 90% of LEARNING criteria. One fixed arm was baited with a hidden food container. Data collection began with the first exposure to the eight-arm MAZE. The total time for each trial and total number of arms visited were observed online and recorded. Nandrolone decanoate (5mg/μl/10min) were injected into hippocampus by stereotaxic implanted guide cannulae. The percentage of fails or successes to consumption of chow were collected and analyzed before and after injection.The results showed that intra-hippocampal nandrolone can impair trained spatial LEARNING approximately 10%. It can impair frequency arm entries 10%. It postulated that a single high dose of the nandrolone can affect important synaptic components involved in hippocampal plasticity. It concludes that nandrolone can impair LEARNING and memory.

Objectives: Proper structure and function of mammal’s CNS is based on inborn neuronal function. Sensory experience based-development deeply affects these processes in the critical period. Some studies reveal that change in sensory experience can influence mammal’s LEARNING and memory. The aim of this study is to investigate about effects of change in visual experience on rat’s spatial LEARNING and memory through using MWM (Morris water MAZE).Materials & Methods: This experimental study was carried out on 30 Wistar male rats at 45 days old which randomly distributed in 3 groups; the CO (Control) group was in 12 light/12 dark cycle through birth to the end of the study, the LR (Light Reared) group was in complete light (24 hours) and the DR (Dark Reared) group was in complete darkness (n=10 for each group). Using MWM, the animals learned to find a hidden platform for 4 trials/day at 5 days. After removing platform, spatial memory has been tested at day 5 in one trial. Time & distance were spent in the correct quadrant measured and analyzed by two-way ANOVA test.Results: Our results indicate that in the LEARNING stage, the CO rats spent less time and distance to find the hidden platform than the other groups (p<0.0001). There was no difference between all groups in probe trial.Conclusion: Change in visual experience impairs rat's spatial LEARNING and spatial memory formation doesn't be influenced.