Investigating the effects of hearing loss in rats and guinea pigs

Abstract

Experimentally induced hearing loss in laboratory animals can lead to subsequent changes in the central nervous system. These central changes following hearing loss may lead to alterations in cognition and anxiety. In our laboratory, rats and guinea pigs are used to study the effects of cochlear trauma with the selected species dependent on the parameters of interest. Guinea pigs’ relatively large and easily accessible cochlea makes the species well suited for cochlear physiological and neural measurements, whereas rats have the advantage of well-established performance on a wide variety of behavioral tests. In a recent study, we investigated whether these well-established tests in rats for stress (open field test; OFT), and learning and memory (novel object recognition; NOR; Morris Water Maze; MWM) could be used in guinea pigs to investigate changes in behavior following conductive hearing loss. Analysis showed that guinea pigs could be trained in the MWM, and showed a similar range of behaviors as described for rats in OFT; however, NOR tests could not be interpreted as most guinea pigs did not interact with the novel objects. Overall, anxiety, spatial learning, and memory were not affected by 8 weeks of conductive hearing loss.