Long-term use was associated with thinning of the posterior cingulate cortex , thickening of the anterior cingulate cortex , and decreased neocortical 5-HT2A receptor binding .
Despite the high method ological heterogeneity and the small sample sizes , the results suggest that hallucinogens increase introspection and positive mood by modulating brain activity in the fronto-temporo-parieto-occipital cortex
Serotonergic hallucinogens produce alterations of perceptions , mood , and cognition , and have anxiolytic , antidepressant , and antiaddictive properties .
These drugs act as agonists of frontocortical 5-HT2A receptors , but the neural basis of their effects are not well understood .
Thus , we conducted a systematic review of neuroimaging studies analyzing the effects of serotonergic hallucinogens in man .
Neuronal correlates of visual and auditory alertness in the DMT and ketamine model of psychosis
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 5HT2A agonist and N-methyl-D-aspartic acid ( NMDA ) antagonist model of psychosis . Fourteen healthy volunteers participated in a r and omized 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 pre central 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
Long-term use was associated with thinning of the posterior cingulate cortex , thickening of the anterior cingulate cortex , and decreased neocortical 5-HT2A receptor binding .
Despite the high method ological heterogeneity and the small sample sizes , the results suggest that hallucinogens increase introspection and positive mood by modulating brain activity in the fronto-temporo-parieto-occipital cortex
Serotonergic hallucinogens produce alterations of perceptions , mood , and cognition , and have anxiolytic , antidepressant , and antiaddictive properties .
These drugs act as agonists of frontocortical 5-HT2A receptors , but the neural basis of their effects are not well understood .
Thus , we conducted a systematic review of neuroimaging studies analyzing the effects of serotonergic hallucinogens in man .