5-HT1A Receptor Activation before Acute Stress Counteracted the Induced Long-Term Behavioral Effects

• Published in: Annals of the New York Academy of Sciences 2004-06, Vol.1018 (1), p.333-338
• Main Authors: RIOJA, J, SANTÍN, L J., GARCÍA, M, DOÑA, A, DE PABLOS, L, CUADRADO, M I, ALCALDE, F J, GONZÁLEZ-BARÓN, S, AGUIRRE, J A
• Format: Article
• Language: English
• Subjects: 5-HT1A receptors; 8-Hydroxy-2-(di-n-propylamino)tetralin - pharmacology; acute stress; Animals; Behavior, Animal; corticosterone; Immobilization; Male; passive avoidance; Piperazines - pharmacology; Pyridines - pharmacology; Rats; Rats, Sprague-Dawley; Serotonin 5-HT1 Receptor Agonists; Serotonin Antagonists - pharmacology; Serotonin Receptor Agonists - pharmacology; Stress, Physiological - metabolism
• ISSN: 0077-8923; 1749-6632
• DOI: 10.1196/annals.1296.041

: The long‐term behavioral consequences of acute immobilization (IMMO) in rats and the effects of 5‐HT1A receptor activation (8‐OH‐DPAT: 0.3 mg/kg, sc) were studied. Corticosterone levels after IMMO with previous 8‐OH‐DPAT treatment were also studied. Twenty‐four hours after IMMO (3 h), rats performed conditioned (passive avoidance) and unconditioned (escape behavior) anxiety tests in the elevated T maze. Pre‐exposure to IMMO induces long‐term behavioral changes in contrast with control rats. These behavioral alterations include an increase of anxiogenic responses, such as exploratory behavior and passive avoidance response. This effect was counteracted by 8‐OH‐DPAT pretreatment and reversed by WAY‐100635 when administered before 8‐OH‐DPAT. Serum corticosterone levels increased during the first hour of stress and after 8‐OH‐DPAT administration. Our results support the hypothesis that involvement of acute stress is crucial in the anxiety‐like behaviors and in the potentiation of fear. The activation of 5‐HT1A receptors counteracted the long‐term effects induced by IMMO.