Brain mechanisms of hallucinogens and entactogens
Dialogues in Clinical Neuroscience December 31, 2001 DOI: 10.31887/dcns.2001.3.4/fxvollenweider via OpenAlex
Summary
AI-generated from the abstractA review of brain imaging and behavioral studies finds that classic hallucinogens like psilocybin and dissociative anesthetics like ketamine produce overlapping psychotic syndromes marked by increased activity in the prefrontal cortex and changes in temporoparietal, striatal, and thalamic regions, suggesting a common final pathway. Both drug classes disrupt sensory gating in rats by acting on serotonin 5-HT(2) receptors in cortico-striato-thalamic circuitry, indicating that disruption of cortico-subcortical processing leading to sensory overload of the cortex is a shared feature of these psychoses. In contrast, the entactogen MDMA produces positive mood and activates prefrontolimbic and paralimbic structures while deactivating the amygdala and thalamus.
Study at a glance
| Characteristics | Review Peer reviewed |
|---|---|
| Population | Humans and rats |
| Topics | MDMA Mescaline Psilocybin Serotonin |
| Keywords | Hallucinogen Neuroscience Psychotomimetic Psychology |
| Citations | 127 |
| Key finding | Classic hallucinogens and dissociative anesthetics produce overlapping psychotic syndromes and disrupt sensory gating via a common pathway involving cortico-striato-thalamic circuitry, while MDMA produces a distinct emotional state with different brain activation patterns. |
Abstract
This review focuses on recent brain imaging and behavioral studies of sensory gating functions, which assess similarities between the effects of classic hallucinogens (eg, psilocybin), dissociative anesthetics (eg, ketamine), and entactogens (eg, 3,4-methylenedioxymethamphetamine [MDMA]) in humans. Serotonergic hallucinogens and psychotomimetic anesthetics produce overlapping psychotic syndromes associated with a marked activation of the prefrontal cortex (hyperfrontality) and other overlapping changes in temporoparietal, striatal, and thalamic regions, suggesting that both classes of drugs act upon a common final pathway. Together with the observation that both hallucinogens and N-methyl-oaspartate (NMDA) antagonists disrupt sensory gating in rats by acting on 5-hydroxytryptamine (serotonin) 5-HT(2) receptors located in cortico-striato-thalamic circuitry these findings suggest that disruption of cortico-subcortical processing leading to sensory overload of the cortex is a communality of these psychoses. In contrast to hallucinogens, the entactogen MDMA produces an emotional state of positive mood, concomitant with an activation of prefrontolimbiclparalimbic structures and a deactivation of amygdala and thalamus.