Behavioural and microdialysis study after neurotoxic lesion of the dorsal raphe nucleus in rats.
The study investigated the effects of a 5,7-dihydroxytryptamine (5,7-DHT) lesion of the dorsal raphe nucleus (DRN) on anxiety-related behaviour and neurochemical correlates in rats. Behaviour was assessed in the elevated plus maze test (X-maze). Lesion of the DRN reduced markedly 5-HT levels in projection areas by at least 60%. Destruction of the serotonergic neurons in the DRN changed neither anxiety-related behaviour on the elevated plus maze, nor aversion-induced 5-HT release in the brain. Exposure of the lesioned rats to the elevated plus maze increased extracellular 5-HT (148%) in the ventral hippocampus similar as in sham-lesioned (162%) and non-lesioned (160%) controls. The results demonstrate that lesioning of 5-HT neurons in the DRN does not abolish totally the control of anxiety-related behaviour.
Rex
André
A
Institute of Pharmacology and Toxicology, School of Veterinary Medicine, Freie Universität Berlin, Koserstr. 20, D-14195, Berlin, Germany. andrerex@zedat.fu-berlin.de
Thomas
Heike
H
Hörtnagl
Heide
H
Voits
Mechthild
M
Fink
Heidrun
H
D000818:Animals; D001007:Anxiety / Q000378:metabolism*; D008297:Male; D018782:Maze Learning / Q000502:physiology*; D017551:Microdialysis / Q000379:methods*; D011903:Raphe Nuclei / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012701:Serotonin / Q000378:metabolism*
D012701:Serotonin