The Effect of Different Doses of Melatonin on Learning and Memory Deficit in Alzheimer Model of Rats

Background: Alzheimer Disease (AD) is an age-related neurodegenerative disorder with a progressive impairment of cognitive function. The pineal gland hormone melatonin (MEL) has been known as protection agent against AD. However, the effect in various doses inconsistent. Objectives: In this study, we aimed to investigate two MEL on learning and memory amyloid-βeta (Aβ)-induced AD rats. Materials & Methods: Forty-eight male Wistar rats were used experiment randomly divided control, sham, vehicle, AD, AD+MEL10 mg/kg, AD+MEL 20 mg/kg groups. Intracerebroventricular injection Aβ1–42 was develop animal model Also, MEL-treated groups received intraperitoneal for 4 next weeks. Morris Water Maze (MWM) Passive Avoidance Learning (PAL) tests examine animals’ memory. brain animals removed immunohistochemistry anti- Amyloid Precursor Protein (APP). Results: Intra-peritoneal significantly improve MWM (P=0.000) PAL test (P=0.000), but there no significant changes that (P>0.05). Histopathological analysis revealed clearance APP deposition AD+MEL20 group considerable compared (P=0.000). Conclusion: Our findings indicate 10 have similar results model. But more deposition.