Neuronal correlates of visual and auditory alertness in the DMT and ketamine model of psychosis
Jörg Daumann, Daniel Wagner, Karsten Heekeren, Anna Neukirch, Christiane M. Thiel, Euphrosyne Gouzoulis‐mayfrank
Journal of Psychopharmacology March 20, 2009 DOI: 10.1177/0269881109103227 (opens in new tab)
Study at a glance
AI-extracted from the abstract| Characteristics | Randomized double-blind crossover fMRI study Peer reviewed |
|---|---|
| Sample size | 14 |
| Population | Healthy volunteers |
| Interventions | DMT S-ketamine |
| Topics | DMT Esketamine Ketamine |
| Citations | 62 |
| Key points | DMT reduced BOLD response during alertness tasks, especially in extrastriate and temporal regions, with stronger visual effects; S-ketamine increased activation in left insula and precentral gyrus during auditory alerting. Authors suggest potential differences and overlaps in schizophrenia pathomechanisms, but note conclusions are preliminary. |
Abstract
Deficits in attentional functions belong to the core cognitive symptoms in schizophrenic patients. Alertness is a nonselective attention component that refers to a state of general readiness that improves stimulus processing and response initiation. The main goal of the present study was to investigate cerebral correlates of alertness in the human 5HT(2A) agonist and N-methyl-D-aspartic acid (NMDA) antagonist model of psychosis. Fourteen healthy volunteers participated in a randomized double-blind, cross-over event-related functional magnetic resonance imaging (fMRI) study with dimethyltryptamine (DMT) and S-ketamine. A target detection task with cued and uncued trials in both the visual and the auditory modality was used. Administration of DMT led to decreased blood oxygenation level-dependent response during performance of an alertness task, particularly in extrastriate regions during visual alerting and in temporal regions during auditory alerting. In general, the effects for the visual modality were more pronounced. In contrast, administration of S-ketamine led to increased cortical activation in the left insula and precentral gyrus in the auditory modality. The results of the present study might deliver more insight into potential differences and overlapping pathomechanisms in schizophrenia. These conclusions must remain preliminary and should be explored by further fMRI studies with schizophrenic patients performing modality-specific alertness tasks.