The role of 5-HT in response inhibition and re-engagement.

In animal and human research, the neurotransmitter serotonin (5-HT) has been implicated in inhibitory control. Using functional magnetic resonance imaging (fMRI), the present study investigated the acute effects of pharmacological modulation of the serotonergic system on brain activation during response inhibition and re-engagement in healthy human volunteers. In a randomized double-blind placebo-controlled cross-over design 14 men received either a single oral dose of the selective serotonin reuptake inhibitor (SSRI) escitalopram (10mg) or a placebo.

Vulnerability to psychotogenic effects of ketamine is associated with elevated D2/3-receptor availability.

Previous positron emission tomography (PET) studies employing competition paradigms have shown either no change or substantial declines in striatal [(11)C]-raclopride binding after challenge with psychotogenic doses of the N-methyl-D-aspartate antagonist ketamine. We sought to probe the relationship between the severity of ketamine-induced psychotic symptoms and altered dopamine D(2/3) receptor availability throughout brain using the high affinity ligand [(18)F]-fallypride (FP). PET recordings were obtained in a group of 10 healthy, young male volunteers, in a placebo condition, and in the course of an infusion with ketamine at a psychotomimetic dose.

Serotonergic modulation of response inhibition and re-engagement? Results of a study in healthy human volunteers.

Objective: Cognitive functions dependent on the prefrontal cortex, such as the ability to suppress behavior (response inhibition) and initiate a new one (response re-engagement) is important in the activities of daily life. Central serotonin (5-HT) function is thought to be a critical component of these cognitive functions. In recent studies, 5-HT failed to affect stop-signal reaction time (SSRT), a fundamental process in behavioral inhibition.

Differential effects of escitalopram on attention: a placebo-controlled, double-blind cross-over study.

Rationale: The role of serotonin (5-HT) in attention is not fully understood yet.

Objective: We aimed to investigate whether attention is modulated after treatment with escitalopram, a selective serotonin reuptake inhibitor (SSRI).

Methods: We administered 10 mg of escitalopram to 20 healthy subjects in a placebo-controlled, double-blind cross-over design for 1 day or to another 20 participants for a period of 7 days.

The impact of ziprasidone in combination with sertraline on visually-evoked event-related potentials in depressed patients with psychotic features.

Background: The use of atypical antipsychotics in major depression complicated by psychotic features has not been extensively investigated. Event-related potentials (ERP) have been reported to be impaired in depressed patients, probably due to serotonergic hypofunction. The objective of this study was to examine the effects of a combination therapy with ziprasidone and sertraline on ERP in major depression with psychotic features.