Woodruff, Randall Thomas. Effects of staphylococcal enterotoxin A on impulsivity and spatial cognition in C57BL/6 mice. Retrieved from https://doi.org/doi:10.7282/T3KS6QMB
DescriptionBackground & Aims: Bacterial antigens have shown to cause cognitive deficits and impulsivity in mice that has been thought to be the result of an activated immune system. However these findings could be due to other factors, such as sickness behavior, which could interfere with the behavioral assessments of cognition and impulsivity. Staphylococcal enterotoxin A (SEA) is a bacterial superantigen that does not induce sickness behaviour in mice. The aim of this study was to investigate the effects of SEA on spatial cognition and impulsivity. Methods: Saline or SEA (5 µg i.p) was injected in C57BL6 mice (n=8 per group). Changes in impulsivity were assessed on a 24-32 second differential reinforcement of low response rates schedule of reinforcement and changes in cognition were assessed with the Morris water navigation task (hidden platform and probe trial) after a single or repeated injections of SEA. Results: SEA significantly decreased the number of food pellets mice earned (P= .01) but showed no effect on efficiency ratios (reinforced nose pokes / total nose pokes) with respect to controls, when tested on the DRL schedule. Compared with controls, SEA also increased stereotypy like behavior in mice, with increased responding after food reinforcement (P=.001) in the DRL schedule. Morris water navigation task showed decreases in latency and distance traveled to reach platform across days both in single (P< 0.05) and repeatedly (P<0.005) injected mice. However no differences in performance were seen between SEA and controls. Conclusion: Injection of SEA does not affect spatial cognition or induce impulsive behavior in mice; however, SEA induces behavioral changes similar to stereotypy.