The effects of lorazepam on extrastriatal dopamine D(2/3)-receptors-A double-blind randomized placebo-controlled PET study.

Lorazepam is a widely used anxiolytic drug of the benzodiazepine class. The clinical actions of benzodiazepines are thought to be mediated via specific allosteric benzodiazepine binding sites and enhancement of GABAergic neurotransmission in the brain. However, the indirect effects of benzodiazepines on other neurotransmitter systems have not been extensively studied.

Cortical glutamate-dopamine interaction and ketamine-induced psychotic symptoms in man.

Rationale: The noncompetitive glutamate N-methyl-D: -aspartate receptor antagonist ketamine induces transient psychotic symptoms in man. Involvement of dopaminergic mechanisms in these effects has been suggested.

Objectives: The purpose of this article is to study the effects of ketamine on extrastriatal dopamine receptor availability in healthy subjects and extracellular dopamine levels in rat cortex.

The amygdala and schizophrenia: a volumetric magnetic resonance imaging study in first-episode, neuroleptic-naive patients.

Background: The attempts to evaluate amygdaloid volumes using magnetic resonance imaging (MRI) in patients with schizophrenia have yielded highly divergent results.

Methods: Volumes of the amygdala were measured in 22 healthy participants and 18 neuroleptic-naive patients with first-episode schizophrenia, while controlling for intracranial area, gender, age, and handedness.

Results: Persons with schizophrenia presented significantly lower amygdaloid volumes bilaterally.

Measurement of striatal and thalamic dopamine D2 receptor binding with 11C-raclopride.

11C-Raclopride is a widely used positron emission tomography (PET) tracer for measurement of striatal D2 dopamine receptor binding characteristics. Recently, 11C-raclopride has also been used for quantification of thalamic D2 receptor binding. We studied reproducibility and validity issues on the thalamic D2 binding measurements using healthy volunteer test-retest data and simulated data.