Sex-specific interhemispheric brain oscillation asymmetries in an ADHD rat model
Marcus Vinicius Soares de Lara1, Gabriel Cardozo Muller2, Leticia Barbieri Caus3
1Graduate Program in Biological Sciences/Biochemistry, NeurAging Lab, Department of Biochemistry, Institute of Basic Health Sciences, Federal University of Rio Grande do Sul, Porto Alegre, RS 90035 003, Brazil.
Neuroscience
|December 3, 2025
Summary
Sex differences in brain oscillation patterns may be key to understanding Attention-Deficit Hyperactivity Disorder (ADHD) and its emotional comorbidities. Our study in rat models reveals distinct hemispheric asymmetries in female ADHD brains, not linked to neurotransmitter transporter levels.
Area of Science:
- Neuroscience
- Psychiatry
- Animal Models
Background:
- Attention-Deficit Hyperactivity Disorder (ADHD) is a neurodevelopmental disorder with sex-specific manifestations.
- Electroencephalogram (EEG) brain oscillations are implicated in psychiatric disorders, but sex-based interhemispheric analyses in ADHD are lacking.
Purpose of the Study:
- To investigate sex differences in brain oscillation asymmetries and their correlation with behavioral and neurochemical markers in an ADHD rat model.
- To explore the relationship between interhemispheric brain activity and dopamine transporter (DAT) and norepinephrine transporter (NET) levels in ADHD.
Main Methods:
- Utilized spontaneously hypertensive rats (SHR, ADHD model) and Wistar Kyoto rats (WKY, control) of both sexes.
- Implanted subdural electrodes for EEG recordings and conducted open field tasks for behavioral analysis.
- Analyzed immunocontent of DAT and NET in the frontal cortex.
Main Results:
- ADHD model rats exhibited hyperactivity in the open field task.
- Female SHR rats showed significant alpha, beta, and gamma band power asymmetries in the frontal cortex (right > left).
- NET immunocontent displayed a rightward pattern in WKY rats' frontal cortex, but no significant association was found between brain oscillation asymmetries and DAT/NET levels in female SHR rats.
Conclusions:
- Observed sex differences in brain oscillation asymmetries in the ADHD model suggest a potential role in ADHD neurobiology.
- The identified asymmetries in female ADHD rats resemble patterns seen in mood disorders, hinting at shared neurobiological mechanisms and emotional comorbidities.
- Further research into these sex-specific oscillatory patterns is crucial for understanding ADHD and its associated conditions.
