Psychopharmacology
July 26, 2012
André Schmidt, Michael Kometer, Rosilla Bachmann et al.
94 citations
RationaleBoth glutamate and serotonin (5-HT) play a key role in the pathophysiology of emotional biases. Recent studies indicate that the glutamate N-methyl-D-aspartate (NMDA) receptor antagonist ketamine and the 5-HT receptor agonist psilocybin are implicated in emotion processing. However, as yet, no study has systematically compared their contribution to emotional biases.ObjectivesThis study...
Zurich Open Repository and Archive (University of Zurich)
2012
André Schmidt
Recent studies into the molecular, pharmacological and behavioral basis of psychotomimetics such as the glutamate N-methyl- D -aspartate receptor (NMDAR) antagonist ketamine and the mixed 5- hydroxytryptamine (5-HT) receptor agonist psilocybin in healthy human subjects suggest that both the glutamatergic and serotonergic system are implicated in the pathophysiolology of psychotic disorders such...
Pharmacopsychiatry
September 1, 2011
Milan Scheidegger, Anke Henning, Martin Walter et al.
Background: Ketamine is a potent NMDA receptor antagonist with rapid antidepressant properties at subanaesthetic doses. This multimodal imaging study reveals the effects of a subanaesthetic ketamine infusion on fMRI-BOLD responses during an emotional processing task and their relationship to glutamatergic metabolite concentrations in the pregenual anterior cingulate cortex (PACC) assessed by...
Fundamental and Clinical Pharmacology
June 2, 2011
Marko A. Peltoniemi, Teijo I. Saari, Nora M. Hagelberg et al.
44 citations
Ketamine is an intravenous anaesthetic and analgesic agent but it can also be used orally as an adjuvant in the treatment of chronic pain. This study investigated the effect of the herbal antidepressant St John's wort, an inducer of cytochrome P450 3A4 (CYP3A4), on the pharmacokinetics and pharmacodynamics of oral S-ketamine. In a randomized cross-over study with two phases, 12 healthy subjects...
European Journal of Pain
November 8, 2009
Nora M. Hagelberg, Marko A. Peltoniemi, Teijo I. Saari et al.
55 citations
BACKGROUND: Oral ketamine is used as an adjuvant in the treatment of refractory neuropathic and cancer-related pain. Drug interactions may alter the analgesic or other effects of ketamine. AIM AND METHODS: The aim of the study was to investigate the effect of cytochrome P450 3A enzyme inhibition with clarithromycin on the pharmacokinetics and pharmacodynamics of oral S-ketamine in a randomized...
Journal of Psychopharmacology
March 20, 2009
Jörg Daumann, Daniel Wagner, Karsten Heekeren et al.
62 citations
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...
Psychopharmacology
November 2008
Jörg Daumann, Karsten Heekeren, Anna Neukirch et al.
Attentional deficits are common symptoms in schizophrenia. Recent evidence suggests that schizophrenic patients show abnormalities in spatial orienting of attention, particularly a deficit of inhibition of return (IOR). IOR is mostly thought to reflect an automatic, inhibitory mechanism protecting the organism from redirecting attention to previously scanned, insignificant locations....
Human Psychopharmacology Clinical and Experimental
June 11, 2008
Alexander Heinzel, Rainer Steinke, Thorsten Dirk Poeppel et al.
22 citations
OBJECTIVE: We aimed to probe for regional cerebral effects of S-ketamine on in vivo GABA-A-receptor binding in healthy human subjects. METHODS: We investigated I-123-iomazenil SPECT before, during and after administration of S-ketamine in a blinded placebo-controlled study design (n = 12 in both groups). Analyses of SPECT were performed with voxel-based statistical parametric mapping (SPM), and...
Psychopharmacology
May 16, 2008
Karsten Heekeren, Jörg Daumann, Anna Neukirch et al.
158 citations
RATIONALE: Many studies have reported deficits of mismatch negativity (MMN) in schizophrenic patients. Pharmacological challenges with hallucinogens in healthy humans are used as models for psychotic states. Previous studies reported a significant reduction of MMN after ketamine (N-methyl-D-aspartate acid [NMDA] antagonist model) but not after psilocybin (5HT2A agonist model). OBJECTIVES: The...
Neuropsychopharmacology
February 2006
Euphrosyne Gouzoulis‐mayfrank, Karsten Heekeren, Anna Neukirch et al.
Patients with schizophrenia exhibit disturbances of orienting of attention. However, findings have been inconsistent. Pharmacologic challenges with hallucinogens have been used as models for psychosis. The NMDA antagonist state (PCP, ketamine) resembles undifferentiated psychoses with positive and negative symptoms, while the 5-HT(2A) agonist state (LSD, dimethyltryptamine (DMT)) is thought to...