Sustained housing-type social buffering following social housing in male rats

Abstract

In social animals, recovery from the adverse effects of distressing stimuli is promoted by subsequent cohousing with a conspecific animal(s). This phenomenon has been termed housing-type social buffering. We previously found that social housing induced housing-type social buffering in fear-conditioned male rats. This buffering took the form of attenuated conditioned hyperthermia in response to an auditory conditioned stimulus (CS). Here, we assessed whether this social buffering is sustained even if the subject is housed alone after a period of social housing. When fear-conditioned subjects were housed alone during a 48-h period between conditioning and re-exposure to the auditory CS, they exhibited conditioned hyperthermia in response to the CS. However, conditioned hyperthermia was not observed when the 12-h period of social housing began 24 and 36h after conditioning during the 48-h period. This was not the case when the 12-h period of social housing began 0 and 12h after the conditioning. These results suggest that housing-type social buffering is sustained for 12h after the 12-h period of social housing. We next considered whether increasing the duration of social housing would extend the period of social buffering. We observed social buffering of conditioned hyperthermia 24 and 48, but not 96h after a 24-h period of social housing. These results suggest that social buffering was extended when the duration of social housing was increased. Taken together, our findings indicate that housing-type social buffering is sustained after a period of social housing.