Defecation follows digestion, and is a necessary process by which organisms eliminate a solid, semisolid, or liquid waste material known as feces from the digestive tract via the anus. The act has a variety of names ranging from the common, like pooping or crapping, to the technical, e.g. bowel movement, to the obscene (shitting), to the euphemistic, to the juvenile. The topic, usually avoided in polite company, can become the basis for some potty humour.
The laboratory mouse or lab mouse is a small mammal of the order Rodentia which is bred and used for scientific research or feeders for certain pets. Laboratory mice are usually of the species Mus musculus. They are the most commonly used mammalian research model and are used for research in genetics, physiology, psychology, medicine and other scientific disciplines. Mice belong to the Euarchontoglires clade, which includes humans. This close relationship, the associated high homology with humans, their ease of maintenance and handling, and their high reproduction rate, make mice particularly suitable models for human-oriented research. The laboratory mouse genome has been sequenced and many mouse genes have human homologues. Lab mice sold at pet stores for snake food can also be kept as pets.
The Morris water navigation task, also known as the Morris water maze, is a behavioral procedure mostly used with rodents. It is widely used in behavioral neuroscience to study spatial learning and memory. It enables learning, memory, and spatial working to be studied with great accuracy, and can also be used to assess damage to particular cortical regions of the brain. It is used by neuroscientists to measure the effect of neurocognitive disorders on spatial learning and possible neural treatments, to test the effect of lesions to the brain in areas concerned with memory, and to study how age influences cognitive function and spatial learning. The task is also used as a tool to study drug-abuse, neural systems, neurotransmitters, and brain development.
The radial arm maze was designed by Olton and Samuelson in 1976 to measure spatial learning and memory in rats. The original apparatus consists of eight equidistantly spaced arms, each about 4 feet long, and all radiating from a small circular central platform. At the end of each arm there is a food site, the contents of which are not visible from the central platform.
An animal model is a living, non-human, often genetic-engineered animal used during the research and investigation of human disease, for the purpose of better understanding the disease process without the risk of harming a human. Although biological activity in an animal model does not ensure an effect in humans, many drugs, treatments and cures for human diseases are developed in part with the guidance of animal models. Animal models representing specific taxonomic groups in the research and study of developmental processes are also referred to as model organisms. There are three main types of animal models: Homologous, Isomorphic and Predictive. Homologous animals have the same causes, symptoms and treatment options as would humans who have the same disease. Isomorphic animals share the same symptoms and treatments, only. Predictive models are similar to a particular human disease in only a couple of aspects. However, these are useful in isolating and making predictions about mechanisms of a set of disease features.
The golden spiny mouse gets its name from the reddish-orange spiny fur that covers its body from head to tail. This coarse, inflexible fur is thought to protect it from predation. Aside from the golden fur that covers its head and upper parts, its flanks are yellow and its underside is pale. It has gray legs with pale feet and black soles. It is also described as having a small, but distinct white spot under each eye. It is often found in the wild missing a part or all of its tail because it is able to shed this as a defense mechanism. However, it is not known how this is done, how often it can occur, or under what conditions. It lives an average of three years in the wild. It is omnivorous and feeds on seeds, desert plants, snails, and insects. Living in desert regions, it is a xeric animal that obtains water from the plants that it eats and produces very concentrated urine in order to conserve water. A. russatus is naturally nocturnal, but adapts to being diurnal when it shares a habitat with A. cahirinus.
C57BL/6, often referred to as "C57 black 6", "B6", "C57" or "black 6", is a common inbred strain of laboratory mouse.
Genes, Brain and Behavior is a peer-reviewed online-only scientific journal covering research in the fields of behavioral, neural, and psychiatric genetics. It is published by Wiley-Blackwell on behalf of the International Behavioural and Neural Genetics Society. The journal was established in 2002 as a quarterly and is currently published monthly. G2B is a hybrid open access journal, but two years after publication all content is available for free online.
The elevated plus maze (EPM) is a test measuring anxiety in laboratory animals that usually uses rodents as a screening test for putative anxiolytic or anxiogenic compounds and as a general research tool in neurobiological anxiety research such as PTSD and TBI. The model is based on the test animal's aversion to open spaces and tendency to be thigmotaxic. In the EPM, this anxiety is expressed by the animal spending more time in the enclosed arms.
Ambidirectional dominance occurs in a situation where multiple genes influence a phenotype and dominance is in different directions depending on the gene. For example, for gene A increased height is dominant, while for gene B decreased height is dominant. The opposite situation, where all genes show dominance in the same direction, is called directional dominance. In the same example, for both genes A and B increased height is dominant. According to Broadhurst, ambidirectional dominance is the result of stabilising selection in the evolutionary past. Ambidirectional dominance has been found for exploratory behaviours in mice and paradise fish.
Wim E. Crusio is a Dutch behavioral neurogeneticist and a directeur de recherche with the French National Centre for Scientific Research in Talence, France.
Jacqueline N. Crawley is an American behavioral neuroscientist and an expert on rodent behavioral analysis. Since July 2012, she is the Robert E. Chason Chair in Translational Research in the MIND Institute and professor of psychiatry and behavioral sciences at the University of California, Davis School of Medicine in Sacramento. Previously, from 1983–2012, she was chief of the Laboratory of Behavioral Neuroscience in the intramural program of the National Institute of Mental Health. Her translational research program focuses on testing hypotheses about the genetic causes of autism spectrum disorders and discovering treatments for the diagnostic symptoms of autism, using mouse models. She has published more than 275 peer-reviewed articles in scientific journals and 110 review articles and book chapters. According to Scopus, her works have been cited over 36,000 times, giving her an h-index of 99. She has co-edited 4 books and is the author of What's Wrong With my Mouse? Behavioral Phenotyping of Transgenic and Knockout Mice, which was very well received.
Animal models of depression are research tools used to investigate depression and action of antidepressants as a simulation to investigate the symptomatology and pathophysiology of depressive illness or used to screen novel antidepressants.
In animal behaviour, stereotypy, stereotypical or stereotyped behaviour has several meanings, leading to ambiguity in the scientific literature. A stereotypy is a term for a group of phenotypic behaviours that are repetitive, morphologically identical and which possess no obvious goal or function. These behaviours have been defined as 'abnormal', as they exhibit themselves solely in animals subjected to barren environments, scheduled or restricted feedings, social deprivation and other cases of frustration, but do not arise in 'normal' animals in their natural environments. These behaviours may be maladaptive, involving self-injury or reduced reproductive success, and in laboratory animals can confound behavioural research. Stereotypical behaviours are thought to be caused ultimately by artificial environments that do not allow animals to satisfy their normal behavioural needs. Rather than refer to the behaviour as abnormal, it has been suggested that it be described as "behaviour indicative of an abnormal environment".
The hole-board test (HBT) is an experimental method used in scientific research to measure anxiety, stress, neophilia and emotionality in animals. Because of its ability to measure multiple behaviors it is a popular test in behavioral pharmacology, but the results are controversial.
The development of an animal model of autism is one approach researchers use to study potential causes of autism. Given the complexity of autism and its etiology, researchers often focus only on single features of autism when using animal models.
LM22A-4 is a synthetic, selective small-molecule partial agonist of TrkB (EC50 for TrkB activation = 200–500 pM; IC50 for inhibition of BDNF binding to TrkB = 47 nM; IA = ~85%), the main receptor of brain-derived neurotrophic factor. It has been found to possess poor blood-brain-barrier penetration when administered systemically, so LM22A-4 has been given to animals instead via intranasal administration, with central nervous system TrkB activation observed. The compound produces neurogenic and neuroprotective effects in animals, and shows beneficial effects on respiration in animal models of Rett syndrome.
The light-dark box test (LDB) is a popular animal model used in pharmacology to assay unconditioned anxiety responses in rodents. The extent to which behavior in the LDB measures anxiety is controversial.
Pierre L. Roubertoux is a French behavioral geneticist.
The Hebb–Williams maze is a maze used in comparative psychology to assess the cognitive ability of small animals such as mice and rats. It was developed by Donald O. Hebb and his student Kenneth Williams in 1946, when both men were working at Queen's University at Kingston. A modified version, intended specifically to measure the intelligence of rats, was described in a 1951 paper by Hebb's students Rabinovitch and Rosvold. This modified version is the most commonly used in research where the aim is to measure animals' problem-solving abilities. In general, animals are tested in the Hebb–Williams maze's twelve separate mazes after acclimating to six practice mazes, though some studies have not used all twelve testing mazes. The two main procedures for the maze are the reward conditioning task and the water escape task. The maze has been used to investigate strain and sex differences in mice. A 2018 study argued that the maze is potentially useful for translational research in fragile X syndrome in humans.
