• The Korean Journal of Physiology and Pharmacology
• /
• v.13 no.5
• /
• pp.357-360
• /
• 2009

It is hypothesized that a number of environmental factors affect animals' behavior. Without controlling these variables, it is very hard for researchers to get not only reliable, but replicable data from various behavioral experiments testing animals' cognitive as well as emotional functions. For example, laboratory mice which had restricted environment showed different synaptic potentiation properties with wild mice (Zhao MG et al., 2009). While performing behavioral experiments, however, it is sometimes inevitable that the researcher changes the animals' environments, as by switching the cages in which experimental animals are housed and separating animals raised together into small experimental groups. In this study, we investigated the effect of environmental changes on mice's emotional behaviors by socially isolating them or reducing the size of their cage. We found that social isolation selectively increases the animals' levels of anxiety, while leaving depression-like behaviors unchanged. On the other hand, alteration of the housing dimensions affected neither their anxiety levels nor their depression-like behaviors. These results suggest that environmental variables may have a prominent impact on experimental animals' emotional behaviors and possibly their psychological states, leading to bias in the behavioral data produced from experiments.

• The Korean Journal of Physiology and Pharmacology
• /
• v.23 no.1
• /
• pp.81-87
• /
• 2019

Ketamine has long been used as an anesthetic agent. However, ketamine use is associated with numerous side effects, including flashbacks, amnesia, delirium, and aggressive or violent behavior. Ketamine has also been abused as a cocktail with ecstasy, cocaine, and methamphetamine. Several studies have investigated therapeutic applications of ketamine, demonstrating its antidepressant and anxiolytic effects in both humans and rodents. We recently reported that neonatal maternal separation causes enhanced anxiety- and aggressive-like behaviors in adolescent. In the present study, we evaluated how acute and chronic ketamine administration affected the behavioral consequences of neonatal maternal separation in adolescent mice. Litters were separated from dams for 4 hours per day for 19 days beginning after weaning. Upon reaching adolescence (post-natal day 35-49), mice were acutely (single injection) or chronically (7 daily injections) treated with a sub-anesthetic dose (15 mg/kg) of ketamine. At least 1 h after administration of ketamine, mice were subjected to open-field, elevated-plus maze, and resident-intruder tests. We found that acute ketamine treatment reduced locomotor activity. In contrast, chronic ketamine treatment decreased anxiety, as evidenced by increased time spent on open arms in the elevated-plus maze, and remarkably reduced the number and duration of attacks. In conclusion, the present study suggests that ketamine has potential for the treatment of anxiety and aggressive or violent behaviors.

• Journal of Microbiology
• /
• v.40 no.1
• /
• pp.11-19
• /
• 2002

Mice immunized with equine herpesvirus type-1(EHV-1) L-particles skewed a significant increase (p<7.75) in serum antibody titers. Upon a booster dose four weeks lateral antibody titers increased significantly. Interestingly, immunization via intravenous or intramuscular route induced significantly higher (p<0.75) antibody titers. However, mice iummunized with UV-treated L-particles, visions or immunization via intranasal route induced lower antibody titers. Upon challenge inoculation with wildtype EHV-1, our data showed there was a poor correlation between antibody titers and protection against virus replication. Therefore, the role of cell-mediated immunity Inwards protection was investigated. As predicted, the strongest cell-mediated immunity, as measured by delayed-hypersensitivity test, was detected in mice immunized with live virus particles. The magnitude of cell-mediated immune response correlated with the efficacy of L-particles as immunizing agent. The highest efficacy, as indicated in mice immunized via intranasal routed was highly correlated with cell-mediated immunity. A similar phenomenon was also demonstrated in mice immunized intranasally with UV-treated L-particles. However, the degree of protection was reduced when mice immunized intravenously or intramuscularly with UV-treated L-particles. In conclusion, protection conferred in these animals was highly implicated by immune cells and the least by antibodies. The route of immunization and the nature of the antigen also contributed to the efficacy of L-particles as immunizing agent. In contrast to that of herpes simplex virus type 1, our data showed EHV-1 non-infectious L-particles are highly suitable for immunization of the host against EHV-1 disease.

• International Journal of Stem Cells
• /
• v.9 no.2
• /
• pp.186-191
• /
• 2016

Background and Objectives: With the global demand for dairy protein for consumption growing annually, there has been increasing activity in the research field of dairy protein synthesis and production. From a manipulation perspective, it is more difficult to use live cattle for laboratory studies on the production of milk as well as of dairy protein such as casein, as compared with using laboratory animals like rodents. Therefore, we aimed to develop a mouse model of bovine mammary alveolar ducts for laboratory-scale studies. We studied the formation of the bovine mammary gland ductal structure by transplanting the MAC-T bovine alveolar cell line into mice. Methods and Results: MAC-T cells ($1{\times}10^7$) were suspended in Matrigel and injected into the dorsal tissue of 8-week-old male BALB/C nude mice. Histological analysis of tissue dissected from the MAC-T cell-transplanted mice after 6 weeks showed the typical morphology of the tubuloalveolar female gland, as well as glands made up of branching ducts that were surrounded by smooth muscle with small alveoli budding off the ducts. In addition, the epithelial markers CK14 and CK18 were expressed within the duct-like structure. Prolactin was detected in the duct interior in these CK14+ and CK18+ cells but not in the non-transplanted MAC-T cells. Conclusions: These results showed that duct-like tissue had been successfully formed after 6 weeks of transplantation of the CK14+ and CK18+ MAC-T cells into mice dorsal tissue. This mouse model will be a useful tool for further research on the bovine mammary gland.

• Korean Journal of Clinical Laboratory Science
• /
• v.51 no.3
• /
• pp.344-350
• /
• 2019

We investigated the distribution of chigger mites in Seogwipo, Jeju Island to conduct surveillance for the presence of Orientia tsutsugamushi. Using a total of 20 samplers, chigger mite larvas were sampled weekly from September to November in Rice field, Field, Waterway, and Glass field (4 locations), and we found up to 51 larvas of 3 different species of chigger mites. 64 field mice were captured when sampling for chigger mite-infested rodents in rice fields, waterways, fields, reservoirs and hills (5 locations) for 9 months from March, 2018 to November, using 100 Sherman traps with placing 20 traps in each location, and in each location the trap index was 0.08. Only back-striped field mice (Apodemus agrarius) were captured one at a time. They were most frequently captured in April with 15 mice, and then 436 chigger mites were collected from the total of 64 captured wild rodent, showing a chigger index of 6.8. The chigger index was the highest in November at 46.0, followed by 6.8 in July and 4.6 in June. PCR was performed to investigate if there were any O. tsutsugamushi hosts among the 487 chigger mites sampled from the captured rodents and this turned out to be negative.

• Journal of Life Science
• /
• v.24 no.3
• /
• pp.290-296
• /
• 2014

The present experiment investigated putative anxiolytic-like effects of quercetin using an elevated plus-maze (EPM) and hole-board apparatus test in mice. Quercetin is a flavonoid widely distributed in nature. Quercetin (1.25, 2.5, 5, or 10 mg/kg) was orally administered to ICR mice 1 h before a behavioral evaluation in the EPM. Control mice were treated with an equal volume of vehicle, and positive control mice were treated with buspirone (2 mg/kg, i.p.). The mice administered quercetin (5 mg/kg) spent a significantly longer percentage of time in the open arms of the EPM and their percentage of entries into the open arms was significantly increased compared to the vehicle-treated controls (p<0.05). The anxiolytic-like activities of quercetin were antagonized by trans-4-aminocrotonic acid (a $GABA_{A-{\rho}}$ agonist, 20 mg/kg) but not by flumazenil (a $GABA_A$ antagonist, 10 mg/kg) or WAY-100635 (a $5-HT_{1A}$ antagonist, 0.3 mg/kg). Moreover, there were no changes in the locomotor activity or myorelaxant effects in any group compared with the vehicle-treated controls. In the hole-board apparatus test, the number of head-dips increased significantly in the single treatment with quercetin (5 mg/kg) group compared to the vehicle-treated controls (p<0.05). These findings suggest that quercetin can promote anxiolytic-like activity, mediated by the GABAergic nervous system, in mice.

• Proceedings of the Zoological Society Korea Conference
• /
• 1998.10b
• /
• pp.123.2-123
• /
• 1998

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
• /
• 1995.10b
• /
• pp.129.2-129
• /
• 1995

No Abstract, See Full Text

• Proceedings of the Zoological Society Korea Conference
• /
• 1996.10a
• /
• pp.81.2-81
• /
• 1996

No Abstract, See Full Text

• Proceedings of the Korean Nuclear Society Conference
• /
• 2005.05a
• /
• pp.992-993
• /
• 2005