1. Intracranial self-stimulation reverses impaired spatial learning and regulates serum microRNA levels in a streptozotocin-induced rat model of Alzheimer disease
- Author
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Riberas-Sanchez, Andrea, Puig-Parnau, Irene, Vila-Soles, Laia, Garcia-Brito, Soleil, Aldavert-Vera, Laura, Segura- Torres, Pilar, Huguet, Gemma, and Kadar, Elisabet
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Neurons -- Health aspects ,Streptozocin -- Health aspects ,MicroRNA -- Health aspects ,Advertising executives -- Health aspects ,Proteins -- Health aspects ,Alzheimer's disease -- Health aspects ,Health ,Psychology and mental health - Abstract
Background: The assessment of deep brain stimulation (DBS) as a therapeutic alternative for treating Alzheimer disease (AD) is ongoing. We aimed to determine the effects of intracranial self-stimulation at the medial forebrain bundle (MFB-ICSS) on spatial memory, neurodegeneration, and serum expression of microRNAs (miRNAs) in a rat model of sporadic AD created by injection of streptozotocin. We hypothesized that MFB-ICSS would reverse the behavioural effects of streptozotocin and modulate hippocampal neuronal density and serum levels of the miRNAs. Methods: We performed Morris water maze and light-dark transition tests. Levels of various proteins, specifically amyloid-[beta] precurser protein (APP), phosphorylated tau protein (pTAU), and sirtuin 1 (SIRT1), and neurodegeneration were analyzed by Western blot and Nissl staining, respectively. Serum miRNA expression was measured by reverse transcription polymerase chain reaction. Results: Male rats that received streptozotocin had increased hippocampal levels of pTAU S202/T205, APP, and SIRT1 proteins; increased neurodegeneration in the CA1, dentate gyrus (DG), and dorsal tenia tecta; and worse performance in the Morris water maze task. No differences were observed in miRNAs, except for miR-181c and miR-let-7b. After MFB-ICSS, neuronal density in the CA1 and DG regions and levels of miR-181c in streptozotocin-treated and control rats were similar. Rats that received streptozotocin and underwent MFB-ICSS also showed lower levels of miR-let-7b and better spatial learning than rats that received streptozotocin without MFB-ICSS. Limitations: The reversal by MFB-ICSS of deficits induced by streptozotocin was fairly modest. Conclusion: Spatial memory performance, hippocampal neurodegeneration, and serum levels of miR-let-7b and miR-181c were affected by MFB-ICSS under AD-like conditions. Our results validate the MFB as a potential target for DBS and lend support to the use of specific miRNAs as promising biomarkers of the effectiveness of DBS in combatting AD-associated cognitive deficits., Introduction Alzheimer disease (AD), the most prevalent aging-related neurodegenerative disease, is characterized by progressive memory loss and cognitive dysfunction in older adults. (1) Although the underlying molecular mechanisms for AD [...]
- Published
- 2024
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