Scratching is a main behavioral response accompanied by acute and chronic itch conditions, and has been quantified as an objective correlate to assess itch in studies using laboratory animals. Scratching has been counted mostly by human annotators, which is a time-consuming and laborious process. It has been attempted to develop automated scoring methods using various strategies, but they often require specialized equipment, costly software, or implantation of device which may disturb animal behaviors. To complement limitations of those methods, we have adapted machine learning-based strategy to develop a novel automated and real-time method detecting mouse scratching from experimental movies captured using monochrome cameras such as a webcam. Scratching is identified by characteristic changes in pixels, body position, and body size by frame as well as the size of body. To build a training model, a novel two-step J48 decision tree-inducing algorithm along with a C4.5 post-pruning algorithm was applied to three 30-min video recordings in which a mouse exhibits scratching following an intradermal injection of a pruritogen, and the resultant frames were then used for the next round of training. The trained method exhibited, on average, a sensitivity and specificity of 95.19% and 92.96%, respectively, in a performance test with five new recordings. This result suggests that it can be used as a non-invasive, automated and objective tool to measure mouse scratching from video recordings captured in general experimental settings, permitting rapid and accurate analysis of scratching for preclinical studies and high throughput drug screening.
Animals ; Animals, Laboratory ; Behavior, Animal ; Body Size ; Complement System Proteins ; Decision Trees ; Drug Evaluation, Preclinical ; Humans ; Injections, Intradermal ; Machine Learning ; Methods ; Mice ; Motion Pictures as Topic ; Pruritus ; Research Design ; Sensitivity and Specificity ; Video Recording

Preclinical neuroimaging allows for the assessment of brain anatomy, connectivity, and function in laboratory animals, such as mice and this imaging field has been a rapidly growing aimed at bridging the translation gap between animal and human research. The progress in the animal research could be accelerated by high-resolution in vivo optical imaging technologies. Optical coherence tomography-based angiography (OCTA) estimates the scattering from moving red blood cells, providing the visualization of functional micro-vessel networks within tissue beds in vivo without a need for exogenous contrast agents. Recent advancement of OCTA methods have expanded its application to neuroimaging of small animal models of brain disorders. In this paper, we overview the recent development of OCTA techniques for blood flow imaging and its preclinical applications in neuroimaging. In specific, a summary of preclinical OCTA studies for traumatic brain injury, cerebral stroke, and aging brain on mice is reviewed.
Aging ; Angiography ; Animal Experimentation ; Animals ; Animals, Laboratory ; Brain ; Brain Diseases ; Brain Injuries ; Contrast Media ; Erythrocytes ; Humans ; Mice ; Models, Animal ; Neuroimaging ; Optical Imaging ; Stroke ; Tomography, Optical Coherence

Efficient behavioral assays are crucial for understanding the neural mechanisms of cognitive functions. Here, we designed a high-throughput automatic training system for spatial cognition (HASS) for free-moving mice. Mice were trained to return to the home arm and remain there during a delay period. Software was designed to enable automatic training in all its phases, including habituation, shaping, and learning. Using this system, we trained mice to successfully perform a spatially delayed nonmatch to sample task, which tested spatial cognition, working memory, and decision making. Performance depended on the delay duration, which is a hallmark of working memory tasks. The HASS enabled a human operator to train more than six mice simultaneously with minimal intervention, therefore greatly enhancing experimental efficiency and minimizing stress to the mice. Combined with the optogenetic method and neurophysiological techniques, the HASS will be useful in deciphering the neural circuitry underlying spatial cognition.
Animals ; Automation, Laboratory ; instrumentation ; Behavior, Animal ; Equipment Design ; Habituation, Psychophysiologic ; Male ; Memory, Short-Term ; Mice, Inbred C57BL ; Spatial Memory

Mouse is a commonly used animal in life science studies and is classified as outbred if genetically diverse and inbred if genetically homogeneous. Outbred mouse stocks, are used in toxicology, oncology, infection and pharmacology research. The National Institute of Food and Drug Safety Evaluation (NIFDS; former the Korea National Institute of Health) have bred ICR mice for more than 50 years. We investigated to provide users with information and promote accountability to the Korl:ICR. To secure the indigenous data, biological characteristics of Korl:ICR were identified by comparing with other ICR stocks. This domestic ICR stock was denominated as ‘Korl:ICR’. Phylogenetic analysis using SNPs indicated that the population stratification of the Korl:ICR was allocated different area with other ICR. In addition, we measured litter size, body weight, body length, various organ weight, hematology and clinical blood chemistry of the Korl:ICR compared to other ICR. Otherwise, there are no significant differences among the biological phenotypes of Korl:ICR and other ICR. These results suggest that as a genetically indigenous source colony, the Korl:ICR is seperated (or independent) stock with other ICR. Also, we confirmed that there is no difference among the Korl:ICR and other ICR on biological phenotypes. Therefore, the Korl:ICR source colony might be a new stock in distinction from other ICR, it is a good milestone in securing ownership of the national laboratory animal resource. The NIFDS expects that the Korl:ICR mice will be useful animal resource for our domestic researchers.
Animals ; Animals, Laboratory ; Biological Science Disciplines ; Body Weight ; Chemistry ; Hematology ; Korea ; Litter Size ; Mice ; Mice, Inbred ICR ; Organ Size ; Ownership ; Pharmacology ; Phenotype ; Polymorphism, Single Nucleotide ; Population Characteristics ; Rodentia ; Social Responsibility ; Toxicology

Inbred mice are an essential animal strain for research as they can improve the reproducibility and reliability of study results. The establishment of new inbred lines is continuing, and new inbred lines are being used in many research fields. C57BL/6 is a mouse laboratory animal that has been developed and used as an inbred strain since early stage of mouse strain development, and, in the 1950s, C57BL/6 was separated into substrains by the Jackson Laboratory (C57BL/6J) and the National Institutes of Health (C57BL/6N). C57BL/6 mice have been used in immunology and antitumor activity studies since the early strain development stage. After the mouse genome was fully described, C57BL/6 mice use in many areas of research has expanded. In particular, immunological characteristics such as those related to cell-mediated immunity and NK cell activity are relatively higher in C57BL/6 mice than in other mice. The C57BL/6NKorl is a stock of C57BL/6N established as part of a localization of experimental animal strategy of the Korean Food and Drug Administration. Based on analysis of single nucleotide polymorphisms (SNPs), C57BL/6NKorl is considered a genetically distinct inbred stock from other C57BL/6N. Various research efforts have been made to describe the characteristics and increase knowledge of the characteristics of C57BL/6Nkorl. The results obtained through these efforts are expected to increase the utilization of C57BL/6Nkorl as a domestic laboratory animal resource and to enhance the reliability of mouse based studies.
Allergy and Immunology ; Animals ; Animals, Laboratory ; Genome ; Immunity, Cellular ; Killer Cells, Natural ; Mice* ; National Institutes of Health (U.S.) ; Polymorphism, Single Nucleotide ; United States Food and Drug Administration

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 (1×10⁷) 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.
Animals ; Animals, Laboratory ; Caseins ; Cattle ; Cell Line ; Epithelial Cells* ; Female ; Humans ; Male ; Mammary Glands, Human* ; Mice* ; Mice, Nude ; Milk ; Muscle, Smooth ; Prolactin ; Regeneration* ; Rodentia

Members of the genus Trichinella are small nematodes that can infect a wide range of animal hosts. However, their infectivity varies depending on the parasite and host species combination. In this study, we examined the susceptibility of 4 species of laboratory rodents, i.e., mice, rats, hamsters, and gerbils to Trichinella papuae, an emerging non-encapsulated Trichinella species. Trichinella spiralis and Trichinella pseudospiralis were also included in this study for comparison. Fifteen animals of each rodent species were infected orally with 100 muscle larvae of each Trichinella species. Intestinal worm burden was determined at day 6 and 10 post-inoculation (PI). The numbers of muscle larvae were examined at day 45 PI. The reproductive capacity index (RCI) of the 3 Trichinella species in different rodent hosts was determined. By day 6 PI, 33.2-69.6% of the inoculated larvae of the 3 Trichinella species became adult worms in the small intestines of the host animals. However, in rats, more than 96% of adult worms of all 3 Trichinella species were expelled from the gut by day 10 PI. In gerbils, only 4.8-18.1% of adult worms were expelled by day 10 PI. In accordance with the intestinal worm burden and the persistence of adults, the RCI was the highest in gerbils with values of 241.5+/-41.0 for T. papuae, 432.6+/-48 for T. pseudospiralis, and 528.6+/-20.6 for T. spiralis. Hamsters ranked second and mice ranked third in susceptibility in terms of the RCI, Rats yielded the lowest parasite RCI for all 3 Trichinella species. Gerbils may be an alternative laboratory animal for isolation and maintenance of Trichinella spp.
Animals ; *Animals, Laboratory ; Cricetinae ; *Disease Susceptibility ; Gerbillinae ; Intestines/parasitology ; Male ; Mice ; Muscles/parasitology ; Parasite Load ; Rats ; Rodent Diseases/*parasitology/pathology ; Trichinella/*growth & development ; Trichinellosis/parasitology/pathology/*veterinary

Among several diagnostic tests, a Helicobacter pylori stool antigen (HpSA) test may offer a useful noninvasive method for diagnosing infection without sacrificing animals. In this study, male C57BL/6 mice (n=6) were infected with H. pylori ATCC 49503 (1x10(8) CFU/mouse) by intragastric inoculation three times at 2-day intervals, and H. pylori infected stool specimens were collected 1, 3, 5, 7, 14, 21 days after infection to assess reliability of the HpSA test. Five of six specimens were positive at 5-21 days after infection, and the sensitivity of the HpSA test was 83.33%. The presence of H. pylori infection was confirmed by the rapid urease test and genomic DNA polymerase chain reaction (PCR), and showed the same results as the HpSA. However, the rapid urease test and genomic DNA PCR are invasive tests and require animal sacrifice to detect H. pylori in gastric biopsy samples. We suggest that an HpSA test kit would be useful and effective for monitoring H. pylori in various laboratory animals, as H. pylori can be easily monitored without sacrificing animals.
Animals ; Animals, Laboratory ; Biopsy ; Diagnostic Tests, Routine ; DNA ; Helicobacter ; Helicobacter pylori ; Humans ; Male ; Mice ; Polymerase Chain Reaction ; Urease

The drug resistance of microorganisms isolated from laboratory animals never treated with antibiotics is being reported consistently, while the number of laboratory animals used in medicine, pharmacy, veterinary medicine, agriculture, nutrition, and environmental and health science has increased rapidly in Korea. Therefore, this study examined the development of antimicrobial resistance in bacteria isolated from laboratory animals bred in Korea. A total of 443 isolates (7 species) containing 5 Sphingomonas paucimobilis, 206 Escherichia coli, 60 Staphylococcus aureus, 15 Staphylococcus epidermidis, 77 Enterococcus faecalis, 27 Citrobacter freundii, 35 Acinetobacter baumannii were collected from the nose, intestine, bronchus and reproductive organs of ICR mice and SD rats. Of these species, Acinetobacter baumannii and Enterococcus faecalis showed significant antimicrobial resistance according to the minimum inhibition concentration (MIC) in E-test. In case of Acinetobacter baumannii, several isolates showed MIC values 16-128 microg/mL for cefazolin and cefoxitin, and higher resistance (128-512 microg/mL) to nitrofurantoin than that of standard type. Resistance to cefazolin, cefoxitin and nitrofurantoin was detected in 17.14, 20.00, and 8.57% of the Acinetobacter baumannii isolates, respectively. In addition, 44.1% of the Enterococcus faecalis isolates collected from the laboratory animals were resistant to oxacillin concentration of 16-32 microg/mL range, while MIC value of standard type was below oxacillin concentration of 6 microg/mL. These results suggest that in rodent species of laboratory animals, Acinetobacter baumannii are resistance to cefazolin, cefoxitin and nitrofurantoin, whereas those of Enterococcus faecalis were resistance to oxacillin.
Acinetobacter baumannii ; Agriculture ; Animals ; Animals, Laboratory ; Anti-Bacterial Agents ; Bacteria ; Bronchi ; Cefazolin ; Cefoxitin ; Citrobacter freundii ; Drug Resistance ; Drug Resistance, Microbial ; Enterococcus faecalis ; Escherichia coli ; Intestines ; Korea ; Mice ; Mice, Inbred ICR ; Nitrofurantoin ; Nose ; Oxacillin ; Pharmacy ; Rats ; Rodentia ; Sphingomonas ; Staphylococcus aureus ; Staphylococcus epidermidis ; Veterinary Medicine

This study was designed to analyze the prevalence rates of laboratory animal allergy (LAA) in laboratory workers who perform researches with animals, and detect the mouse urinary allergen (Mus m 1) level in animal facilities for the purpose of establishing program for prevention of exposure to allergen. Study subjects were 240 employees who were working for two animal research institutions in Korea. Then the questionnaire and skin prick tests (SPTs) using twenty allergens were conducted with them. Presence of Mus m 1 in each air borne sample collected from animal facility was determined by using enzyme-linked immunosorbent assay. Through 240 questionnaire sheets, we found that; (1) 17.0% of workers in the direct exposure group answered that they had allergic symptoms due to laboratory animals; and (2) 6.2% of them had asthmatic symptoms. Twenty one subjects (27.6%) among the subjects with common allergens positive result and five subjects (6.6%) among the subjects with negative result showed a positive response to LAA under the SPTs. The Mus m 1 concentration (1.339 ng/m3) in the sample collected during cage exchange in mouse breeding room was up to 2.8 times higher than its concentration (0.483 ng/m3) in the sample collected at the stationary state. We suggest that LAA management programs including control of exposure to laboratory animal allergens should be considered as a measure to reduce the incidence of LAA and relieve the laboratory worker's allergic sensitivity to laboratory animals.
Allergens ; Animal Experimentation ; Animals ; Animals, Laboratory ; Breeding ; Enzyme-Linked Immunosorbent Assay ; Hypersensitivity ; Incidence ; Korea ; Mice ; Prevalence ; Surveys and Questionnaires ; Skin