The Characterization of Cooperative String-pullung Behavior in Rats After Exposure to Space Flight Stressors

Astronauts work cooperatively to complete tasks on missions through deep space where they will experience stressors, including radiation and sleep fragmentation, that may impair performance. Animals work together to achieve a common goal during cooperative tasks using string-pulling behaviors. While string-pulling behavior has revealed deficits in rat sensorimotor function after exposure to space flight stressors, it has yet to be determined if rats will engage in cooperative string-pulling or if these stressors will influence cooperation. Thus, to explore how space flight stressors impact cooperative behavior, female Wistar rats were exposed to either sham (n = 8) or 10 centi-grays of 250 MeV/n Helium (n = 8) and sleep fragmentation at ~6 months of age. During testing, rats were placed in two separate apparati sharing one string (0.2 cm diameter, 162 cm length, 100% cotton) and were required to pull in the string to retrieve Cheerio rewards simultaneously. Twelve trials/day were provided, and behavior was video recorded for offline analyses of cooperative performance, motivation, and sensorimotor function between groups. Irradiated rats took more days to reach criterion (cooperation on 8/12 trials) than sham rats. Criterion percentage was similar between groups once met; yet the amount of pulling between rat pairs during cooperative trials was greater for the sham group. These results suggest that a low dose exposure to Helium negatively impacts cooperation between female rats. If astronauts display similar disruptions after exposure to space flight stressors, then deleterious effects on team dynamics may arise and compromise mission success.