title: The role of cortical serotonin in anxiety and locomotor activity in Wistar rats.
abstract: The brain's serotonergic system is known to play an important role in the modulation of anxiety. While the role of serotonin (5-HT) in subcortical structures is well investigated, little is known about the function of cortical 5-HT. The present series of studies used local injections of the serotonergic neurotoxin, 5,7-dihydroxytryptamine (5,7-DHT), into the medial prefrontal cortex (mPFC), entorhinal cortex (EC), or occipital cortex (OccC) of rats to chronically reduce 5-HT neurotransmission in these brain areas. The animals were tested for anxiety-like behavior on the elevated plus-maze and open field. An 82% depletion of 5-HT from the mPFC increased anxiety-like behavior, while no general motor effects were evident. In contrast, a 63% 5-HT-depletion of the EC or a 78% 5-HT-depletion of the OccC did not have any effects on emotional or exploratory behaviors. These findings are in line with a proposed role of 5-HT in the mPFC in the modulation of anxiety- and stress-mediated behavior and demonstrate a functional differentiation between different cortical 5-HT projections.
authors.affiliation: Institute of Physiological Psychology and Center for Biological and Medical Research, University of Düsseldorf, Düsseldorf, Germany.
authors.forename: M E
authors.initials: ME
authors.lastname: Pum
authors.forename: J P
authors.initials: JP
authors.lastname: Huston
authors.forename: C P
authors.initials: CP
authors.lastname: Müller