title: 5-HT1A receptor activation counteracted the effect of acute immobilization of noradrenergic neurons in the rat locus coeruleus.
abstract: The aim of our study was to evaluate the effect of acute stress and the 5-HT(1A) receptor involvement in both, the hippocampus noradrenaline (NA) tissue levels and the c-Fos immunoreactivity (c-Fos-IR) in the catecholaminergic neurons of the locus coeruleus (LC). Double immunocytochemical staining of tyrosine hydroxilase (TH) and c-Fos protein combined with stereological techniques were used to study the specific cell activation in the LC neurons in five experimental groups (control group, immobilization (1h) group, 8-OH-DPAT group (8-OH-DPAT 0.3mg/kg, s.c.), DPAT+IMMO group (8-OH-DPAT 0.3mg/kg, s.c., 30' prior acute immobilization) and WAY+DPAT+IMMO group (WAY-100635 0.3mg/kg, s.c. and 8-OH-DPAT 0.3mg/kg, s.c., 45'and 30', respectively, before immobilization). The results showed that hippocampal NA tissue levels and c-Fos-IR in the TH positive neurons of the LC were significantly increased immediately and after 90', respectively, after the immobilization period. Pre-treatment with 8-OH-DPAT counteracted the effects induced by immobilization, but pre-treatment with WAY-100635 did not block the effects induced by 8-OH-DPAT. These results suggest that noradrenaline system is associated in a significant way with immobilization stress. The role of 5-HT(1A) receptor activation in this stress response is also discussed.
authors.affiliation: Department of Human Physiology, School of Medicine, University of Málaga, 29071 Málaga, Spain.
authors.forename: José
authors.initials: J
authors.lastname: Rioja
authors.forename: Luis J
authors.initials: LJ
authors.lastname: Santín
authors.forename: Diana
authors.initials: D
authors.lastname: López-Barroso
authors.forename: Alicia
authors.initials: A
authors.lastname: Doña
authors.forename: Eugenia
authors.initials: E
authors.lastname: Ulzurrun
authors.forename: José A
authors.initials: JA
authors.lastname: Aguirre
mesh_terms: D017371:8-Hydroxy-2-(di-n-propylamino)tetralin / Q000494:pharmacology; D000818:Animals; D002452:Cell Count; D004347:Drug Interactions; D007150:Immunohistochemistry / Q000379:methods; D008125:Locus Coeruleus / Q000473:pathology*; D008297:Male; D009474:Neurons / Q000187:drug effects / Q000378:metabolism*; D009638:Norepinephrine / Q000378:metabolism*; D010879:Piperazines / Q000493:pharmacokinetics / Q000494:pharmacology; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D011725:Pyridines / Q000493:pharmacokinetics / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D044282:Receptor, Serotonin, 5-HT1A / Q000378:metabolism*; D012149:Restraint, Physical / Q000379:methods; D012702:Serotonin Antagonists / Q000494:pharmacology; D017366:Serotonin Receptor Agonists / Q000494:pharmacology; D013315:Stress, Psychological / Q000209:etiology / Q000473:pathology*; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism
chemical_list: D010879:Piperazines; D016760:Proto-Oncogene Proteins c-fos; D011725:Pyridines; D012702:Serotonin Antagonists; D017366:Serotonin Receptor Agonists; D044282:Receptor, Serotonin, 5-HT1A; C090413:N-(2-(4-(2-methoxyphenyl)-1-piperazinyl)ethyl)-N-(2-pyridinyl)cyclohexanecarboxamide; D017371:8-Hydroxy-2-(di-n-propylamino)tetralin; D014446:Tyrosine 3-Monooxygenase; D009638:Norepinephrine