title: Anxiety levels and wild running susceptibility in rats: assessment with elevated plus maze test and predator odor exposure.
abstract: It is reported in the literature that nearly 20% of rats are susceptible to displays of wild running (WR) behavior when submitted to high intensity acoustic stimulation. Some characteristics of WR suggest that it can be viewed as a panic-like reaction. This work aimed to test whether WR-sensitive rats show higher levels of anxiety in elevated-plus-maze (EPM) and predator-odor exposure paradigms in comparison with WR-resistant ones. Male adult Wistar rats were submitted to two trials of acoustic stimulation (104 dB, 60 s) in order to assess WR susceptibility. Seven WR-sensitive and 15 WR-resistant rats were evaluated by the EPM test. Other 13 WR-sensitive and 18 WR-resistant animals were submitted to the predator-odor exposure test which consisted of a 10 min-session of free exploration in a specific apparatus containing two odoriferous stimuli: cotton swab imbedded with snake cloacal gland secretion or with iguana feces (control). WR-sensitive rats presented a significantly higher closed-to open-arm-entry ratio in the EPM test. All rats responded with anxiety-like behaviors to the predator odor exposure, although the WR-sensitive ones showed a marked behavioral inhibition regardless of the odor condition. We conclude that WR-sensitive rats present elevated levels of anxiety manifested by means of passive behavioral strategies.
authors.affiliation: Laboratório de Neurobiologia, Depto. de Ciências Biológicas, Faculdade de Ciências, Universidade Estadual Paulista, Luiz Edmundo Carrijo Coube s/n, CEP 17033 360, Campus de Bauru, SP, Brazil.
authors.forename: Hugo Medeiros Garrido
authors.initials: HM
authors.lastname: de Paula
authors.forename: Amauri
authors.initials: A
authors.lastname: Gouveia
authors.forename: Marcos Vinícius
authors.initials: MV
authors.lastname: de Almeida
authors.forename: Katsumasa
authors.initials: K
authors.lastname: Hoshino
mesh_terms: D000162:Acoustics; D000818:Animals; D004195:Disease Models, Animal; D008297:Male; D018782:Maze Learning; D009812:Odorants; D016584:Panic Disorder / Q000523:psychology*; D011235:Predatory Behavior; D051381:Rats; D017208:Rats, Wistar; D012420:Running; D012903:Smell; D012911:Snakes