Vollenweider Hasler Quednow

Fakultäten » Medizinische Fakultät » Psychiatrische Universitätsklinik » Psychiatrie, Psychotherapie und Psychosomatik, Klinik für » Prof. Dr. Daniel Hell (emeritiert) » Vollenweider Hasler Quednow

Completed research project

Title / Titel Effects of 5-HT2A agonist psilocybin on sensorimotor gating, decision making and psychological measures. A double-blind placebo-controlled dose-effect study in man.
PDF Abstract (PDF, 14 KB)
Summary / Zusammenfassung Prepulse inhibition (PPI) represents the physiological suppression of the startle reflex when an intense acoustic stimulus is preceeded by a weak prepulse. The PPI paradigm is generally accepted as a model for sensorimotor gating processes. Animal studies demonstrate that hallucinogenic 5-HT2A receptor agonists such as DOI disrupt PPI in rats (Vollenweider and Geyer, 2001). Moreover, the fact that 5-HT2 receptor agonists such as psilocybin produce psychosis-like symptoms in man makes this class of compounds an interesting research tool to investigate brain mechanisms underlying psychotic symptom formation and aberrant cognition.

This study aims firstly to investigate the dose dependent effect of the 5-HT2A agonist psilocybin on sensorimotor gating (PPI) in humans, and second to elucidate the relationship of between PPI, psychotic symptom formation and cognitive performance. The plasticity of sensory gating will be assessed by measuring prepulse inhibition and habituation of the acoustic startle reflex. Cognitive performance, decision making, will be investigated using a computerized two-choice prediction task assessing the sequential organization of behavior (Paulus et al, 2000). Subjective effects of psilocybin on mood states are assessed by use of the EWL-60 mood rating scale, and dose-dependent alterations in consciousness are rated via 5-D ASC questionnaires. Finally, the "Positive and Negative Syndrome Scale" (PANSS) is used to collect more data for evaluation of the psilocybin model psychosis paradigm.
Publications / Publikationen Vollenweider FX, Csomor PA, Knappe B, Geyer MA, Quednow BB (2007) The effects of the preferential 5-HT2A agonist psilocybin on prepulse inhibition of startle in healthy human volunteers depend on interstimulus interval. Neuropsychopharmacology 32: 1876-87.

Vollenweider FX, Csomor PA, Paulus M, Geyer MA (2007) Serotonergic neuromodulation of behavioral and cognitive functions in humans. Neuropsychopharmacology 30: S57-S58 Suppl 1.

Keywords / Suchbegriffe sensorimotor gating, PPI, prepulse inhibition, cognition, serotonin, psychosis, decision making, 5-HT2A, psilocybin
Project leadership and contacts /
Projektleitung und Kontakte
PD Dr. F.X. Vollenweider (Project Leader)
Dr. F. Hasler (Project Leader)
Dr. B. Quednow (Project Leader)
Funding source(s) /
Unterstützt durch
Heffter Research Institute (HRI), USA
In collaboration with /
In Zusammenarbeit mit
Prof. M. Paulus, Department of Psychiatry, University of California, San Diego United States
Duration of Project / Projektdauer Aug 2002 to Mar 2007