The vocabulary of the medicine — every key term in psychedelic and ceremonial-medicine neuroscience, defined in plain English.
Explore the research behind these terms across our Neuroscience, Pharmacology, and Clinical Research collections, or browse all articles.
The serotonin 2A receptor — the primary molecular target of classic psychedelics (psilocybin, LSD, DMT, mescaline). Agonism here drives their characteristic perceptual and cognitive effects.
A neurotransmitter regulating mood, cognition, sleep, and perception; the system most psychedelics and MDMA act on.
The protein that reuptakes serotonin from the synapse. MDMA forces it to run in reverse — flooding the synapse with serotonin (a 'releaser') — unlike SSRIs, which block it.
Interconnected brain regions active during self-referential, mind-wandering thought. Psychedelics acutely reduce DMN activity and connectivity, an effect linked to ego dissolution.
The brain's capacity to reorganize its structure and connections. Psychedelics and ketamine promote structural and functional plasticity, including dendritic spine growth.
A developmental window of heightened plasticity. Research suggests psychedelics and MDMA can transiently reopen critical periods for social and emotional learning.
A drug class (e.g., MDMA) producing emotional openness, empathy, and connection without strong hallucinations — mechanistically distinct from classic psychedelics.
A serotonergic hallucinogen acting primarily as a 5-HT2A agonist: psilocybin, LSD, DMT, and mescaline.
A drug class (e.g., ketamine) acting on NMDA glutamate receptors, producing detachment from body and environment — distinct from serotonergic psychedelics.
A glutamate receptor central to learning and memory. Ketamine blocks it, triggering downstream plasticity and rapid antidepressant effects.
The brain's main excitatory neurotransmitter and a downstream mediator of psychedelic- and ketamine-induced plasticity.
Brain-derived neurotrophic factor — a protein supporting neuron growth and synaptic plasticity, upregulated by several psychedelics and by ketamine.
The brain's threat- and fear-processing hub. Psychedelics and MDMA reduce amygdala reactivity to negative stimuli, relevant to trauma and anxiety.
A neuropeptide involved in bonding and trust. MDMA elevates oxytocin, contributing to its prosocial, connection-enhancing effects.
Processes by which fear memories are updated or weakened — a proposed mechanism for MDMA-assisted therapy in PTSD.
A temporary loss of the sense of self during higher-dose psychedelic experiences, correlated with reduced default-mode-network integrity.
A measurable subjective state (unity, sacredness, transcendence of time and space) that predicts therapeutic outcomes in psychedelic trials.
The mindset and the physical/social environment of an experience — major determinants of psychedelic outcomes and safety.
Taking sub-perceptual doses (~one-tenth of a full dose) on a schedule. Evidence for efficacy is mixed and placebo effects are substantial.
A measure of how synchronized activity is between brain regions. Psychedelics increase global connectivity while reducing within-network (e.g., DMN) connectivity.
The brain region for executive function and emotional regulation, and a key site of psychedelic-induced plasticity.
A treatment model pairing a psychedelic or MDMA dose with structured psychotherapy — preparation, dosing, and integration.