Photobiomodulation as a Therapeutic Approach for Attention-Deficit/Hyperactivity Disorder in Model Rats

Abstract Significance: Current treatment options for Attention-deficit/hyperactivity disorder (ADHD) primarily involve pharmacological and behavioral interventions, but concerns about side effects, long-term safety, and limited efficacy in certain populations necessitate alternative therapies. This study investigates the therapeutic potential of Photobiomodulation therapy (PBMT) in an ADHD animal model, contributing to the growing field of nonpharmacological interventions. The study aims to evaluate the effects of PBMT on ADHD symptoms using a spontaneously hypertensive rat (SHR) model. Specifically, it examines whether PBMT can reduce impulsivity and hyperactivity by modulating neuroinflammation, preserving neuronal integrity, and enhancing structural brain connectivity. Methods: SHRs, a well-established ADHD animal model, were used to assess PBMT’s effects. The experimental design included three groups: a normal control group (WKY), an ADHD model group receiving PBMT (SHR25), and an ADHD model group without PBMT intervention (SHR). PBMT was administered daily for 25 seconds at a wavelength of 808 nm over 21 consecutive days. Behavioral assessments (open field test), diffusion tensor imaging (DTI), and immunohistochemical analysis were conducted to evaluate neuroinflammation, neuronal integrity, and myelination. Results: PBMT significantly reduced impulsivity and hyperactivity in SHRs, as indicated by decreased total track length and average speed in the open field test. DTI analysis revealed improved neural connectivity in ADHD-associated brain regions, particularly the prefrontal cortex, striatum, and hippocampus. Immunohistochemical staining demonstrated a significant reduction in Iba-1 positive cells, indicating decreased neuroinflammation. Additionally, PBMT preserved myelin integrity in ADHD-related brain regions, suggesting neuroprotective effects. Conclusions: The findings suggest that PBMT is an effective nonpharmacological intervention for ADHD, reducing impulsivity and hyperactivity while preserving neuronal structure and function. By mitigating neuroinflammation and improving neuronal connectivity, PBMT presents a promising therapeutic alternative to conventional ADHD treatments. Further studies are needed to explore its clinical applicability and long-term safety in human populations.