title: Emotional and risk seeking behavior after prepuberal subchronic or adult acute stimulation of 5-HT7-Rs in Naples High Excitability rats.
abstract: We report here the results of studies aimed to investigate the involvement of serotonin receptor 7 subtype (5-HT7-R) in the modulation of emotional response in Naples High-Excitability (NHE) rat, a validated model for hyperactivity and impaired attention. A range of dosages (0.0, 0.125, 0.250, or 0.500 mg/kg) of LP-211, a selective agonist of 5-HT7-Rs, has been evaluated in animals at different age (adolescence and adulthood). Male NHE and random bred (NRB) control rats were tested in an Elevated Zero-Maze (EZM) after LP-211 treatment in two different regimens: at the issue of adolescent, subchronic exposure (14 intraperitoneal [i.p.] injections, once/day, pnd 31-44, tested on pnd 45--Exp. 1) or as adult, acute effect (15 min after i.p. injection--Exp. 2). Adolescent, subchronic LP-211 at 0.500 mg/kg dosage increased the frequency of head-dips only in NHE rats. Drug effect on time spent and entries in open EZM quadrants were revealed with adult, acute administration of 0.125 mg/kg LP-211 (both strains), indicating a tendency toward anxiolytic effects. In conclusion, data demonstrate that subchronic stimulation of 5-HT7-Rs during prepuberal period increases novelty-seeking/risk-taking propensity in NHE adults. These sequels are revealing increased disinhibition and/or motivation to explore in the NHE rats, which are characterized by a hyperactive dopaminergic system. These data may open new perspectives in studying mechanism of risk-seeking behavior.
authors.affiliation: Department of Experimental Medicine, School of Medicine, Second University of Naples, Naples, Italy.
authors.forename: Lucia A
authors.initials: LA
authors.lastname: Ruocco
authors.forename: Emilia
authors.initials: E
authors.lastname: Romano
authors.forename: Concetta
authors.initials: C
authors.lastname: Treno
authors.forename: Enza
authors.initials: E
authors.lastname: Lacivita
authors.forename: Claudio
authors.initials: C
authors.lastname: Arra
authors.forename: Ugo A
authors.initials: UA
authors.lastname: Gironi-Carnevale
authors.forename: Domenica
authors.initials: D
authors.lastname: Travaglini
authors.forename: Marcello
authors.initials: M
authors.lastname: Leopoldo
authors.forename: Giovanni
authors.initials: G
authors.lastname: Laviola
authors.forename: Adolfo G
authors.initials: AG
authors.lastname: Sadile
authors.forename: Walter
authors.initials: W
authors.lastname: Adriani
mesh_terms: D000367:Age Factors; D000818:Animals; D001288:Attention / Q000187:drug effects; D004644:Emotions / Q000187:drug effects*; D008297:Male; D010879:Piperazines / Q000494:pharmacology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011985:Receptors, Serotonin / Q000378:metabolism*; D012309:Risk-Taking; D017366:Serotonin Receptor Agonists / Q000494:pharmacology*
chemical_list: C573815:N-(4-cyanophenylmethyl)-4-(2-diphenyl)-1-piperazinehexanamide; D010879:Piperazines; D011985:Receptors, Serotonin; D017366:Serotonin Receptor Agonists; C104425:serotonin 7 receptor
keywords: ADHD; LP-211; NHE rats; hyperactivity; zero maze