The effect of vitamin B12 on synaptic plasticity of hippocampus in Alzheimer’s disease model rats

Abstract

Background

Hippocampus cells, responsible for learning and memory, are disturbed in Alzheimer’s disease (AD), resulting in production of several inflammatory markers, such as neurexin 1 –neuroligin, cyclooxygenase–2 (COX–2), and caspase–3 proteins, used in measurement of AD’s severity and development. Vitamin B₁₂, which plays a role in brain functioning, has anti–inflammatory properties and its impairment is associated with apoptosis in Alzheimer’s disease. This study aimed to investigate the effect of vitamin B₁₂ on restoration of Synaptic Plasticity on scopolamine–induced AD in rats.

Methods

To simulate AD, Rats, except the control group were i.p. injected with 3 mg/kg scopolamine. Before scopolamine the pretreatment group vitamin B₁₂ (0.5, 2, and 4 mg/kg) was injected every day for the next 14 days. After 24 h, sectioning the rats’ brains, the concentration of postsynaptic density protein 95 (PSD–95), neurexin 1–neurolgin, COX–2, and caspase–3 proteins in hippocampus were measured using immunoblotting.

Results

B₁₂ significantly enhanced molecular balance. PSD–95 and neurexin 1 and neuroligin concentrations were significantly reduced, whereas COX–2 and activated caspase–3 were enhanced in the hippocampus of scopolamine–injected subjects. Their alterations were decreased after B12 administration.

Conclusions

Vitamin B₁₂ protected scopolamine–injected rats and inhibited hippocampal inflammation and apoptosis and preserved pre– and post–synaptic proteins and possibly synaptic integrity in hippocampus route.

Keywords:

• Vitamin B 12
• hippocampus
• Alzheimer disease (AD)
• postsynaptic density protein 95 (PSD–95)
• neurexin 1
• neurolgin
• COX–2
• caspase–3

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Funding

This study has been supported by a grant from the Deputy of Research and Technology, Golestan University of Medical Sciences, Gorgan, Iran. We would like to thank the Neuroscience Research Center, Gorgan, Iran.