Mohammad Amin Tofighi Zavareh - Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran- Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Mohammad Hossain Kargar Godaneh - Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran- Laser Applications in Medical Sciences Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Parnian Eslahi - Department of Biology and Anatomical Sciences, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
Abbas Aliaghaei - Hearing Disorders Research Center, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran- Laser Applications in Medical Sciences Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran

Background: Insulin promotes the expression of genes related to brain function, thus preventing the neurodegeneration process. The present study was designed to find the neuroprotective effect of insulin by reducing neuron loss in the brain. Materials and Methods: In this study, ۲۰ adult male NMRI mice were divided into two groups: control and insulin. The control group was intact, and the insulin group received ۱۰۰ μL of insulin at a ۷۲-hour interval by intraperitoneal (I.P.) injection for ۳۰ days. At the end of the study, the brain was removed. The volume of the brain and the total number of neurons and glia were estimated by stereological techniques, and also the gene expression of NSR, PI۳K, AKT, IGF-۱, and FOXO-۱ was measured using real-time PCR. Results: The results showed that the total number of neurons decreased in the control group compared to the experimental group. Furthermore, the expression of NSR, PI۳K, AKT, IGF-۱, and FOXO-۱ genes was lower in the control group than in the insulin group. Conclusion: The results showed that treating mice with insulin prevented reducing the number of neurons and gene expression related to normal brain function. So, insulin could have neuroprotective effects against neuron loss. Insulin may be beneficial as a new approach to avoiding neuron loss in regenerative medicine.

Insulin, Brain, Neurons Loss, Aging, PI۳K-Akt Pathway