ABSTRACT
Many experimental approaches require housing rodents in individual cages, a stressful condition for social animals, which may act as a confounding factor for data interpretation. Comparing three groups of Wistar rats - singly housed, singly housed with daily social interaction, and animals kept in pairs - we found that socially isolated animals displayed classical markers of behavioral stress and anhedonia. We then investigated how social isolation may impact the development of epilepsy, a prototypical experimental condition requiring single housing for seizure monitoring. We found that seizures were 25 times more frequent in singly housed animals without social interaction as compared to the other two groups. Isolated animals also showed increased oxidative stress levels. Data obtained from singly housed animals without social interaction is difficult to interpret because results are obtained in a context of behavioral and oxidative stress. Preclinical studies may be strongly affected by such confounding factor.