The five choice serial reaction time task: comparison between Sprague-Dawley and Long-Evans rats on acquisition of task, and sensitivity to phencyclidine.

The 5-choice serial reaction time task (5-CSRTT) allows examination of multiple aspects of cognition/executive functions (attention/impulsivity/ perseveration). Most 5-CSRTT studies are performed with pigmented (i.e. Long-Evans: LE) rats; however, albino strains (i.e. Sprague-Dawley: SD) are more commonly used in behavioural pharmacology experiments. Hence, we compared 5-CSRTT performances of SD and LE rats and their sensitivity to acute phencyclidine (PCP, 1-2.5 mg/kg). SD required significantly fewer sessions(35 versus 50) than LE rats for task acquisition, especially at shortest stimulus light duration (1 s). However,once trained, under vehicle conditions, both strains performed similarly. In contrast, PCP treatment differentially affected the two strains. Thus, whilst percentage of accuracy was decreased for both strains, in SD rats number of premature responses was more markedly decreased, whereas omissions and latency time to correct responses were more notably increased. In addition, PCP monotonically diminished in SD, but augmented (1-1.5 mg/kg) in LE rats compulsive responding. To summarize, under our experimental conditions, the SD offer advantages over LE strain for speed of acquisition of 5-CSRTT. Once trained, basal performances of both strains were equivalent and stable enough for challenge with pharmacological compounds. However, PCP differentially affected the strains on several parameters considered.