This project will employ functional brain imaging to study the mechanism and immediate and long-term effects of psilocybin, a serotonin receptor 2A agonist, on cortical and cortico-subcortical brain networks in healthy adults. Psilocybin shows promise as a safe, transformational therapeutic across several psychiatric conditions. However, little is know about...
Human neuroimaging studies report that psychedelics induce serotonin-2A receptor-dependent changes in functional brain reorganization, presumably reflecting neuromodulation. However, these studies often overlook the potent vasoactive effects of serotonin. Here we identified psilocybin-induced alterations in hemodynamic response functions during human functio...
Mental illness is often characterised by a maladaptive sense of self. The neurobiological basis of Self-Other distinction may provide targets for therapeutic interventions. Psychedelics alter the experience of selfhood, but the neurocomputational mechanism is unclear. We used a computationally-informed behavioural assay to investigate whether psychedelics di...
BackgroundPsychedelics are emerging as promising treatments for major depressive disorder (MDD) and treatment-resistant depression (TRD). Functional magnetic resonance imaging (fMRI) offers a powerful tool to study neural mechanisms underlying therapeutic response.MethodsThis systematic review (PROSPERO #CRD42024557973) examined neuroimaging studies of psilo...
Decades of cross-species research highlight the claustrums extensive bidirectional connectivity with cortical and subcortical regions, implicating it in higher-order cognitive processes requiring synchronized brain states. Psychedelics may disrupt this synchrony by modulating claustro-cortical signaling, reflected by the dissolution of cortical network signa...
Both meditation and psychedelics are widely studied for their therapeutic potential in mental health. Recent research suggests potential synergies between mindfulness practice and psychedelics, though empirical studies have primarily focused on psilocybin. This study investigates the distinct and combined effects of mindfulness practice and an ayahuasca-insp...
In previous clinical trial work, the investigators observed lasting reductions in headache burden after limited dosing of psilocybin. This purpose of this study is to examine potential sources for this observed effect. This study will measure brain resting state functional connectivity (fMRI), central synaptic density (SV2A PET), peripheral markers of inflam...
Serotonergic psychedelics alter self-boundaries and can induce out-of-body experiences (OBEs)-the sense of being located outside one’s physical body. While OBEs also occur in clinical conditions and can be experimentally induced, their neural basis under psychedelics remains underexplored. In an open-label, baseline-controlled MRI study of 62 healthy adults ...
Human neuroimaging with functional Magnetic Resonance Imaging has been a key feature of the current wave of psychedelic research, in both healthy and clinical populations. The available data has suggested that classic psychedelics (psilocybin, LSD, DMT) have a characteristic effect of acutely and profoundly disrupting the normal pattern of resting-state conn...
Psilocybin (PSIL) is a psychedelic drug and a promising experimental therapeutic for many psychiatric conditions. Precision functional mapping (PFM) combines densely repeated resting state fMRI sampling and individual-specific network mapping to improve signal-to-noise ratio (SNR) and effect size in brain imaging research. We present a randomized cross-over ...
This study will examine the synaptotrophic effects of psilocybin among medically healthy, detoxified OUD subjects. Eligible OUD participants will undergo pre- and post- psilocybin administration PET scans with the \[11C\]-UCB-J radiotracer while inpatient. Participants will undergo screening as outpatients at the Clinical Neuroscience Research Unit (CNRU). O...
Background: Functional neurological disorder (FND) is a common cause of neurological symptoms including seizures and movement disorders. It can be debilitating, is associated with high health and social care costs, and can have a poor prognosis. Functional magnetic resonance imaging (fMRI) has suggested FND is a multi-network disorder. Converging evidence su...
This chapter reviews the effects of classic psychedelics on human oscillatory brain activity, as measured by resting-state electroencephalography (EEG) and magnetoencephalography (MEG). Across moderate to high doses of LSD, psilocybin, ayahuasca, and DMT, a consistent reduction in alpha power (8-13 Hz) emerges, particularly in occipital regions. Below 30 Hz,...
ABSTRACT PsiConnect is a large-scale neuroimaging study designed to investigate the neural and subjective effects of psilocybin using multimodal neuroimaging. It combines functional, structural, and diffusion-weighted MRI with EEG to examine brain activity in 62 participants before and after a 19 mg dose of psilocybin. The design includes resting-state scans...
Major Depressive Disorder (MDD) is typically characterized by altered linear functional connectivity (FC) across large-scale brain networks. Yet, it is unclear whether similar alterations are observed when nonlinear FC is examined. This study investigated how antidepressant treatment (i.e., psilocybin and escitalopram) modulates both linear FC and nonlinear ...
Psilocybin is a hallucinogen with complex neurobiological and behavioral effects. This is the first study to use MRI to follow functional changes in brain activity in response to different doses of psilocybin in fully awake, drug naive rats. Female and male rats were given IP injections of vehicle or psilocybin in doses of 0.03 mg/kg, 0.3 mg/kg, and 3.0 mg/k...
Despite divergent behavioral and phenomenological profiles, both psychedelic states and reduced states of consciousness have been associated with a flattening of the brain's functional hierarchy. To address this apparent paradox, we developed a more specific definition of hierarchy based on the proximity of the brain to thermodynamic equilibrium and then app...
Psychedelics are emerging as potential treatments for a range of mental health conditions, including anxiety and depression, treatment-resistant depression, and substance use disorders. Recent studies have also suggested that the psychedelic psilocybin may be able to treat obsessive-compulsive disorder (OCD). Since the 1960s, case studies have reported impro...
