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“Brain mechanisms of hallucinogens and entactogens”.
Dialogues Clin Neurosci. 2001 Dec 28;3(4):265-79.
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-HT2 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.
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