A comparative study of the responses to behavioral, metabolic and painful stimuli of mice housed in conventional (open-top) and individually ventilated (IVC) cage systems

Different cage systems provide species-specific, welfare conditions for the housing of laboratory rats, and conventional (open-top - OTC) and individually ventilated (IVC) cage systems are commonly used. Stress may develop due to the housing of animals; We think that responses to behavioral, metabolic, and painful stimuli may vary. For this reason, we aimed to comparatively examine behavior, painful responses, hormonal and physiological parameters in mice housed in different cages. A total of 48 F2 generation BALB/c albino 8-10 week old male mice were used in our study. Mice housed in OTC and IVC cage systems were divided into four groups as experimental and naive control groups. During the experimental period, the body temperature and body weight of all groups were measured on postnatal days 63-105. Open field tests and elevated plus maze tests were applied to the experimental groups for behavioral analysis, and hot-plate and tail-flick thermal nociceptive tests were performed to investigate painful responses. At the end of these tests, adrenocorticotropic hormone (ACTH), corticosterone (CORT), ghrelin, leptin levels were evaluated by the ELISA method and adrenal weight was measured from blood and plasma taken from mice sacrificed under general anesthesia. Data obtained, Windows SPSS 24 statistical program was used and comparisons; Analyzed with t-test, one-way ANOVA and Mann Whitney U test. Mice housed in IVC had higher body temperature, body weight, adrenal gland weight, and stress level in behavioral tests compared to mice housed in OTC. Responses to thermal painful stimuli in mice in the IVC group were more delayed compared to mice in the OTC group. Compared to the mice in the IVC experimental and naive control groups, the plasma CORT, ACTH, and ghrelin levels were higher and leptin levels were lower than the mice in the OTC experimental and naive control groups. According to this research data, it shows that the stress parameters of mice housed in IVC cages are high and there is also a change in painful responses. As a result, it shows that the stress caused by the procedures and different habitats in the experimental studies can change the study results in mice.