Improved Spatial Memory And Neuroinflammatory Profile Changes in Aged Rats Submitted to Photobiomodulation Therapy

• Published in: Cellular and molecular neurobiology Vol. 42; no. 6; pp. 1875 - 1886
• Main Authors: Cardoso, Fabrízio dos Santos, de Souza Oliveira Tavares, Cristiane, Araujo, Bruno Henrique Silva, Mansur, Fernanda, Lopes-Martins, Rodrigo Álvaro Brandão, Gomes da Silva, Sérgio
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-08-2022; Springer Nature B.V
• Subjects: Alzheimer's disease; Animal memory; Biomedical and Life Sciences; Biomedicine; Brain; Cell Biology; Cerebral cortex; Cerebrospinal fluid; Chemokines; Cognitive ability; Exploratory behavior; Fractalkine; Granulocyte-macrophage colony-stimulating factor; Habituation; Hippocampus; Inflammation; Interleukin 10; Interleukin 5; Interleukin 6; IP-10 protein; Lasers; Memory; Mental task performance; Monocyte chemoattractant protein 1; Neurobiology; Neurodegenerative diseases; Neurosciences; Original Research; Rodents; Spatial discrimination learning; Spatial memory; Traumatic brain injury; Tumor necrosis factor-α; Learning; Aging; Brain; Cognitive function; Photobiomodulation; Cytokine
• ISSN: 0272-4340; 1573-6830
• DOI: 10.1007/s10571-021-01069-4

Recent evidences have shown the therapeutic potential of transcranial photobiomodulation on traumatic brain injury and Alzheimer’s disease. Despite the promising benefits in the brain, little is known about the laser’s effects in the absence of pathological conditions. We submitted young (4 months old) and aged (20 months old) rats to transcranial low-level laser and evaluated their exploratory activity and habituation in open field, anxiety in elevated plus maze, spatial memory in Barnes maze, and aversive memory in a step-down inhibitory avoidance task. Additionally, the levels of a panel of inflammatory cytokines and chemokines were quantified in two different brain regions: the cerebral cortex and the hippocampus. Young and aged rats submitted to transcranial laser exhibited better cognitive performance in Barnes maze than did control rats. Transcranial laser therapy decreased cortical levels of GM-CSF, IL-10, MCP-1, LIX, and TNFα in young rats and IL-5 in aged rats. High levels of IL-6, IL-10, and TNF-alpha were found in the cerebral cortex of aged rats submitted to transcranial laser. In the hippocampus, a decrease in IP-10 and fractalkine levels was observed in the aged rats from the laser group when compared to the aged rats from the control group. Our data indicate that transcranial photobiomodulation improves spatial learning and memory and alters the neuroinflammatory profile of young and aged rats’ brains.