In-vivo modulation of central 5-hydroxytryptamine (5-HT1A) receptor-mediated responses by the cholinergic system.
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.
Haddjeri
Nasser
N
Laboratory of Neuropharmacology & Neurochemistry, Faculty of Pharmacy, University Claude Bernard Lyon I, INSERM U-512, 8 Avenue Rockefeller 69373 Lyon Cedex 08, France. nhaddj@rockefeller.univ-lyon1.fr
Faure
Céline
C
Lucas
Guillaume
G
Mnie-Filali
Ouissame
O
Chouvet
Guy
G
Astier
Bernadette
B
Renaud
Bernard
B
Blier
Pierre
P
Debonnel
Guy
G
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D001285:Atropine / Q000494:pharmacology; D001831:Body Temperature / Q000187:drug effects; D008297:Male; D009043:Motor Activity / Q000187:drug effects; D018727:Muscarinic Antagonists / Q000494:pharmacology; D009474:Neurons / Q000187:drug effects / Q000502:physiology; D010275:Parasympathetic Nervous System / Q000502:physiology*; D017374:Paroxetine / Q000494:pharmacology; D011903:Raphe Nuclei / Q000166:cytology / Q000502:physiology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044282:Receptor, Serotonin, 5-HT1A / Q000187:drug effects*; D012701:Serotonin / Q000502:physiology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D017367:Selective Serotonin Reuptake Inhibitors / Q000494:pharmacology; D013550:Swimming / Q000523:psychology
D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D001285:Atropine; D018727:Muscarinic Antagonists; D017374:Paroxetine; D044282:Receptor, Serotonin, 5-HT1A; D012701:Serotonin; D017366:Serotonin Receptor Agonists; D017367:Selective Serotonin Reuptake Inhibitors