Ketamine psychosis C57BL/6N

Male 12-week-old C57BL/6N mice (Charles River Laboratories, Germany) were used as focal animals. Ketamine hydrochloride was administered once a day for five days (i.p., 30 mg/kg, 5 µl/g). Five days after the last injection, social interactions were assessed in the partition test. Three days after the partition test, a social interaction test in the open field was performed. <b>Partition test</b> The test consisted of habituation and sociability tests, 5 minutes each. During habituation, the actor was introduced to an empty cage (50 ´ 12 ´ 24.5 cm height). The cage was divided into two compartments by a transparent, perforated plastic separator. The smaller compartment (1/4 of the cage) was designated to be the partner’s compartment during the second phase. After habituation, the actor was moved to a transport cage for a short time, during which a partner was placed in his compartment, and immediately afterwards, the actor was introduced to the other part of the cage. <b>Open field test</b> The test consisted of habituation and social interaction tests, 5 minutes each. For habituation, actors were introduced into an empty open field arena (55 ´ 37.5 ´ 20.5 cm height). Next, two wire cups (9 cm diameter, B-0197, Bionovo, Poland) were placed in the cage: one covering an unfamiliar conspecific and one empty (as a novel object).