Paper: "Psilocybin as a Potential Countermeasure to Toxoplasma gondii-Induced Behavioral Modification: A Hypothesis and Proposed Research Framework"

Abstract Toxoplasma gondii, a neurotropic protozoan parasite infecting approximately 2 billion humans worldwide, has been documented to produce significant behavioral modifications in both rodent and human hosts. Current evidence indicates that T. gondii manipulates host dopaminergic and serotonergic pathways, with recent research (Calvo-Urbano et al., 2025) demonstrating dose-dependent correlations between parasite-encoded tyrosine hydroxylase (TgTH) expression and behavioral alterations. Despite this substantial disease burden and accumulating evidence for behavioral effects, no therapeutic interventions currently target the neurological modifications induced by chronic T. gondii infection. Concurrently, psilocybin has emerged as a potent modulator of overlapping neural systems, with demonstrated effects on serotonergic signaling, neuroplasticity, and fear extinction. This paper proposes that psilocybin, through its action on 5-HT2A receptors and downstream effects on dopaminergic systems, may counteract or attenuate the behavioral modifications induced by chronic T. gondii infection. We synthesize current literature on T. gondii neurological mechanisms, psilocybin pharmacology, and convergent neural pathways to establish a testable hypothesis. A three-phase experimental framework is proposed, progressing from rodent behavioral studies to human observational research and ultimately controlled clinical trials. If confirmed, this hypothesis would represent a novel therapeutic approach for the most common parasitic infection affecting human brain function, with implications for mental health treatment paradigms. Keywords: Toxoplasma gondii, psilocybin, behavioral modification, dopamine, serotonin, 5-HT2A, neuroplasticity, fear extinction, psychedelics