The International Journal of Neuropsychopharmacology

Table of Contents - 2004 - Volume 7, Issue 04  


In-vivo modulation of central 5-hydroxytryptamine (5-HT1A) receptor-mediated responses by the cholinergic system

Nasser Haddjeri a1c1, Céline Faure a1, Guillaume Lucas a3, Ouissame Mnie-Filali a1, Guy Chouvet a1, Bernadette Astier a1, Bernard Renaud a1, Pierre Blier a2 and Guy Debonnel a3
a1 Laboratory of Neuropharmacology & Neurochemistry, Faculty of Pharmacy, University Claude Bernard Lyon I, INSERM U-512, 8 Avenue Rockefeller 69373 Lyon Cedex 08, France
a2 Institute of Mental Health Research, University of Ottawa, 1145 Carling, Ottawa, Canada K1Z 7K4
a3 Neurobiological Psychiatry Unit, McGill University, 1033 Pine Avenue West, Montréal, Québec, Canada H3A 1A1

Article author query
haddjeri n   [PubMed][Google Scholar] 
faure c   [PubMed][Google Scholar] 
lucas g   [PubMed][Google Scholar] 
mnie-filali o   [PubMed][Google Scholar] 
chouvet g   [PubMed][Google Scholar] 
astier b   [PubMed][Google Scholar] 
renaud b   [PubMed][Google Scholar] 
blier p   [PubMed][Google Scholar] 
debonnel g   [PubMed][Google Scholar] 

Abstract

The aim of the present study was to investigate a putative modulation of rat 5-HT system by the muscarinic receptor antagonist atropine using in-vivo electrophysiological and behavioural techniques. In the dorsal raphe nucleus, administration of atropine (1 mg/kg i.v.) prevented the suppressant effect of the selective serotonin reuptake inhibitor paroxetine (0.5 mg/kg i.v.) on the spontaneous firing activity of 5-HT neurons, suggesting that atropine could induce an attenuation of somatodendritic 5-HT1A autoreceptors responsiveness. The 5-HT1A receptor agonist 8-OH-DPAT decreased both immobility in the forced swim test and the body core temperature. Pre-treatment with atropine (5 and 10 mg/kg i.p.) enhanced antidepressant-like effect of 8-OH-DPAT (1 mg/kg s.c.) and reduced 8-OH-DPAT (0.1 mg/kg s.c.)-induced hypothermia. In conclusion, the present study reports a functional role of muscarinic receptors in the modulation of pre- and post-synaptic 5-HT1A receptors mediated responses.

(Received October 7 2003)
(Reviewed November 27 2003)
(Revised February 9 2004)
(Accepted February 24 2004)


Key Words: Atropine; dorsal raphe; extracellular unitary recordings; forced swim test; 5-HT1A and muscarinic receptors.

Correspondence:
c1 Dr N. Haddjeri, Laboratory of Neuropharmacology & Neurochemistry, Faculty of Pharmacy, University of Claude Bernard Lyon I, INSERM U-512, 8 Avenue Rockefeller 69373 Lyon Cedex 08, France. Tel.: (33) 4-78-77-75-54 Fax: (33) 4-78-77-72-09 E-mail: nhaddj@rockefeller.univ-lyon1.fr

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