A single dose of the serotonin neurotransmission agonist paroxetine enhances motor output: double-blind, placebo-controlled, fMRI study in healthy subjects.

Full Abstract

Since serotonin (5-HT) stimulates motor function, pharmacological potentiation of 5-HT neurotransmission may improve motor function in healthy subjects and, possibly, recovery in post-stroke patients. Indeed, fluoxetine, a selective serotonin reuptake inhibitor (SSRI), increased activation in executive motor areas of healthy subjects as fenozolone, a releaser of monoamines (including noradrenaline, dopamine, and serotonin) from intracellular stores. This study is intended to test the hypothesis that paroxetine can likewise modulate brain motor activity in a dose-dependent manner in healthy subjects. In a double-blind counterbalanced study, six subjects underwent functional MRI examinations on three sessions 1 week apart (E1, E2, and E3) at the time of peak plasma concentrations (5 h after drug intake, i.e., either 20 or 60 mg of paroxetine or placebo) with a complex sequential opposition task. Rest and activation alternated in a block design. During activation, subjects performed, with the right hand, a 1-Hz-paced task that alternated two fist closings with a sequential opposition task. Paroxetine elicited effects similar to those reported for fluoxetine; notable changes were hyperactivation in the contralateral S1/M1, and posterior SMA and widespread hypoactivation of basal ganglia and cerebellum. There was an inverse correlation between dose and effect: significantly greater effects were observed with the 20-mg dose compared with 60 mg. Paroxetine dose-dependently modulates activation of the entire motor pathway in a way that favors motor output. Thus, a single dose of the SSRI paroxetine reorganized motor processing.

Author information

Author/s: Loubinoux, Isabelle (I); Pariente, Jérémie (J); Boulanouar, Kader (K); Carel, Christophe (C); Manelfe, Claude (C); Rascol, Olivier (O); Celsis, Pierre (P); Chollet, François (F);

Affiliation: INSERM U455, Pavillon Riser, Hôpital Purpan, 31059 Toulouse, France. isabelle.loubinoux(-atsign-)purpan.inserm.fr

Journal and publication information

Publication Type: Clinical Trial; Journal Article; Randomized Controlled Trial; Research Support, Non-U.S. Gov't

Journal: NeuroImage (Neuroimage), published in United States. (Language: eng)

Reference: 2002-Jan; vol 15 (issue 1) : pp 26-36

Dates: Created 2002/01/04; Completed 2002/03/20; Revised 2006/11/15;

PMID: 11771971, status: MEDLINE (last retrieval date: 2/18/2009, IMS Date: 18 Feb 2009 00:00:00)

Sourced from the National Library of Medicine. Abstract text and other information may be subject to copyright.

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