Related Experiment Video
Updated: Aug 10, 2026
Murine Distal Colostomy, A Novel Model of Diversion Colitis in C57BL/6 Mice
Published on: July 12, 2018
[Effects of crowding on immune functions in mice]
K Tsukamoto1, K Machida, Y Ina
1Department of Hygiene and Public Health, School of Human Sciences, Waseda University, Tokorozawa, Japan.
Insights
Crowding significantly impacts mouse immune systems, decreasing lymphocytes and impairing neutrophil function in highly crowded conditions. Moderate crowding may enhance some immune responses, suggesting density is a key stressor.
Area of Science:
- Immunology
- Animal Behavior
- Stress Physiology
Context:
- Crowding is a common environmental stressor in laboratory animal research.
- Understanding crowding's impact on immune function is crucial for experimental validity.
- Previous studies have shown varied effects of crowding on animal health.
Purpose:
- To investigate the effects of different levels of crowding on the immune functions of male BALB/c mice.
- To differentiate the impacts of varying cage densities and spatial constraints on immune cell populations and functions.
- To assess the relationship between social stress induced by crowding and specific immune responses.
Summary:
- Experiment one showed that high crowding (16 mice/cage) significantly decreased lymphocyte percentages and neutrophil phagocytic activity, while increasing neutrophil numbers.
- Moderate crowding (4 mice/small space) in experiment two led to increased plasma IgG levels, with neutrophil function tending towards enhancement.
- Severe crowding (20 mice/cage) in experiment two depressed neutrophil superoxide production and phagocytic activity, similar to experiment one, while humoral immune response to sheep red blood cells (SRBC) showed no significant differences.
Impact:
- Crowding density is a significant stress factor influencing immune system parameters in mice.
- Results highlight the importance of controlled housing conditions to minimize confounding effects of social stress in research.
- Findings suggest a dose-dependent effect of crowding on immune function, with severe crowding detrimental and moderate crowding potentially modulating specific immune aspects.
Abstract:
The effects of several types of crowding on immune functions were studied in mice. This study consisted of two experiments. Experiment one: Male BALB/c mice were initially housed in groups of four mice per cage. After fourteen days of acclimation, the mice were randomly divided into three groups, Control (four mice per cage, control group), Crowd-I (four mice per small space) and Crowd-II (sixteen mice per cage). These conditions were maintained for seven days. The results of experiment one were as follows: (1) The percentage of lymphocytes in the blood of Crowd-II was significantly lower than that of Control (p < 0.05). (2) The percentage of neutrophils and the absolute number of neutrophils in blood of Crowd-II were significantly higher than in Control (p < 0.05). (3) Superoxide production activity (NBT reduction activity) of blood neutrophils in Crowd-II tended to be depressed, and phagocytic activity of neutrophils was significantly depressed in Crowd-II as compared with Control (p < 0.01). These results suggest that the complexity of interrelationships among mice caused by an increase in the number of animals per cage is a very important stress factor. Experiment two: Male BALB/c mice were initially housed in groups of five mice per cage. After fourteen days of acclimation, the mice were divided into three groups, Control (five mice per cage, control group), Crowd-(1) (five mice per cmall space) and Crowd-(2) (twenty mice per cage). In Control and Crowd-(1), the same mice were used as in the acclimation period. These conditions were maintained for seven days. In this period, on the second day, all the mice were injected intraperitoneally with sheep red blood cells (SRBC). The results of experiment two were as follows: (1) The specific humoral immune response to SRBC was investigated in terms of the number of PFC in the spleens and hemagglutination in sera, but significant differences were not found among the groups. (2) Plasma IgG levels in the Crowd-(1) were significantly higher than those in Control (p < 0.05). (3) Both superoxide production activity and phagocytic activity of neutrophils were significantly depressed in Crowd-(2) as compared with Control (p < 0.01, respectively), whereas each neutrophil function of Crowd-(1) tended to be enhanced as compared with Control.
More Related Videos
07:07Evaluation of T Follicular Helper Cells and Germinal Center Response During Influenza A Virus Infection in Mice
Published on: June 27, 2020
05:34Operating and Biocontainment Procedures of a Facility for Laboratory Mice with a Natural Microbiome: Immunophenotyping Procedure
Published on: December 13, 2024