Objective assessment of emotion regulation and resilience in clinical neuropsychology currently relies on self-report, which is subject to bias. This review proposes EEG entropy modulation as a candidate brain-based biomarker. Neural complexity, measured by entropy, reflects the flexible information processing underlying adaptive self-regulation. Evidence shows diminished neural complexity in emotional dysregulation and anxiety, while interventions like mindfulness may restore it. The modulation of entropy during cognitive-emotional tasks, rather than static resting-state measures, provides a more ecologically valid marker of regulatory capacity. Future research should explore task-based entropy modulation in regulatory hubs like the prefrontal cortex and integrate these data with machine learning to identify 'entropy profiles' of dysregulation and predict therapeutic response.
In a study using adult male Sprague Dawley rats, repeated ketamine administration (30 mg/kg for 5 days) induced social withdrawal and reduced social novelty and motivation, mimicking schizophrenia-like symptoms. Subsequent treatment with either the antipsychotic risperidone (6 mg/kg) or an extract of the herbal plant Salix mucronata (5 mg/kg) for 7 days successfully reversed the social deficits. Both treatments also increased brain dopamine and acetylcholine levels. However, the rats showed reduced sucrose preference (indicating anhedonia) and reduced weight gain after ketamine and mild stress, and reduced brain volume was noted in experimental groups. No differences in brain mass were found between controls and treated groups. The findings suggest that S. mucronata has antipsychotic potential similar to risperidone.
Mice lacking the PI3Kγ gene did not respond to standard doses of ketamine or to classic antidepressants such as imipramine and fluoxetine, as measured by the forced swimming test. This unresponsiveness required a chronic deficiency of the PI3Kγ-mediated pathway, not just acute inhibition. The findings suggest PI3Kγ plays a role in antidepressant activity and may be involved in treatment resistance observed in some patients with major depressive disorder.