Anxiety levels and wild running susceptibility in rats: assessment with elevated plus maze test and predator odor exposure.
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.
de Paula
Hugo Medeiros Garrido
HM
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.
Gouveia
Amauri
A
de Almeida
Marcos Vinícius
MV
Hoshino
Katsumasa
K
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