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Lee–Boot Effect
The Lee–Boot effect is a phenomenon concerning the suppression or prolongation of oestrous cycles of mature female mice (and other rodents), when females are housed in groups and isolated from males. It is caused by the effects of an estrogen-dependent pheromone, possibly 2,5-dimethylpyrazine, which is released via the urine and acts on the vomeronasal organ of recipients. This pheromone lowers the concentration of luteinizing hormone and elevates prolactin levels, synchronising or stopping the recipient's cycle. This effect goes some way to explain why spontaneous pseudopregnancy can occur in mice. The same response is invoked from isolated females when brought into contact with urine-soaked bedding from other females' cages. The adrenal glands are required for production of the urine pheromone which is responsible for this effect. See also * Menstrual synchrony * Whitten effect The Whitten effect is stimulation, by male pheromones, of synchronous estrus in a female population. ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oestrous Cycles
The estrous cycle (, originally ) is the set of recurring physiological changes that are induced by reproductive hormones in most mammalian therian females. Estrous cycles start after sexual maturity in females and are interrupted by anestrous phases, otherwise known as "rest" phases, or by pregnancies. Typically, estrous cycles repeat until death. These cycles are widely variable in duration and frequency depending on the species.Bronson, F. H., 1989. Mammalian Reproductive Biology. University of Chicago Press, Chicago, IL, USA. Some animals may display bloody vaginal discharge, often mistaken for menstruation. Many mammals used in commercial agriculture, such as cattle and sheep, may have their estrous cycles artificially controlled with hormonal medications for optimum productivity. The male equivalent, seen primarily in ruminants, is called rut. Differences from the menstrual cycle Mammals share the same reproductive system, including the regulatory hypothalamic system ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pheromone
A pheromone () is a secreted or excreted chemical factor that triggers a social response in members of the same species. Pheromones are chemicals capable of acting like hormones outside the body of the secreting individual, to affect the behavior of the receiving individuals. There are ''alarm signal, alarm pheromones'', ''food trail pheromones'', ''sex pheromones'', and many others that affect behavior or physiology. Pheromones are used by many organisms, from basic unicellular prokaryotes to complex multicellular eukaryotes. Their use among insects has been particularly well documented. In addition, some vertebrates, plants and ciliates communicate by using pheromones. The ecological functions and evolution of pheromones are a major topic of research in the field of chemical ecology. Background The portmanteau word "pheromone" was coined by Peter Karlson and Martin Lüscher in 1959, based on the Greek φερω ''pheroo'' ('I carry') and ὁρμων ''hormon'' ('stimulating'). P ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alkylpyrazine
Alkylpyrazines are chemical compounds based on pyrazine with different substitution patterns. Some alkylpyrazines are naturally occurring highly aromatic substances which often have a very low odor threshold and contribute to the taste and aroma of various foods including cocoa, baked goods, coffee and wines. Alkylpyrazines are also formed during the cooking of some foods via Maillard reactions. Examples File:2-Methylpyrazine.png , 2-Methylpyrazine (found in roasted sesame) File:2,3-Dimethyl Pyrazine Structural Formula V1.svg , 2,3-Dimethylpyrazine (found in roasted sesame) File:2,5-Dimethylpyrazin V1.svg , 2,5-Dimethylpyrazine (asparagus, tea, crispbread, malt, shrimp, soy, squid, Swiss chease, bread, roasted sesame) File:Tetramethylpyrazine.PNG , 2,3,5,6-Tetramethylpyrazine (nattō, fermented cocoa beans) 2-Methylpyrazine 2-Methylpyrazine was the volatile odorant found at the highest concentration in roasted sesame seed oil. 2,3-Dimethylpyrazine 2,3-Dimethylpyrazine is ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Vomeronasal Organ
The vomeronasal organ (VNO), or Jacobson's organ, is the paired auxiliary olfactory (smell) sense organ located in the soft tissue of the nasal septum, in the nasal cavity just above the roof of the mouth (the hard palate) in various tetrapods. The name is derived from the fact that it lies adjacent to the unpaired vomer bone (from Latin 'plowshare', for its shape) in the nasal septum. It is present and functional in all snakes and lizards, and in many mammals, including cats, dogs, cattle, pigs, and some primates. Some humans may have physical remnants of a VNO, but it is vestigial and non-functional. The VNO contains the cell bodies of sensory neurons which have receptors that detect specific non-volatile (liquid) organic compounds which are conveyed to them from the environment. These compounds emanate from prey, predators, and the compounds called sex pheromones from potential mates. Activation of the VNO triggers an appropriate behavioral response to the presence of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Luteinizing Hormone
Luteinizing hormone (LH, also known as luteinising hormone, lutropin and sometimes lutrophin) is a hormone produced by gonadotropic cells in the anterior pituitary gland. The production of LH is regulated by gonadotropin-releasing hormone (GnRH) from the hypothalamus. In females, an acute rise of LH known as an LH surge, triggers ovulation and development of the corpus luteum. In males, where LH had also been called interstitial cell–stimulating hormone (ICSH), it stimulates Leydig cell production of testosterone. It acts synergistically with follicle-stimulating hormone (Follicle-stimulating hormone, FSH). Structure LH is a heteroprotein dimer, dimeric glycoprotein. Each monomeric unit is a glycoprotein molecule; one alpha and one beta subunit make the full, functional protein. Its structure is similar to that of the other glycoprotein hormones, follicle-stimulating hormone (FSH), thyroid-stimulating hormone (TSH), and human chorionic gonadotropin (hCG). The protein dimer ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prolactin
Prolactin (PRL), also known as lactotropin, is a protein best known for its role in enabling mammals to produce milk. It is influential in over 300 separate processes in various vertebrates, including humans. Prolactin is secreted from the pituitary gland in response to eating, mating, estrogen treatment, ovulation and nursing. It is secreted heavily in pulses in between these events. Prolactin plays an essential role in metabolism, regulation of the immune system and pancreatic development. Discovered in non-human animals around 1930 by Oscar Riddle and confirmed in humans in 1970 by Henry Friesen, prolactin is a peptide hormone, encoded by the ''PRL'' gene. In mammals, prolactin is associated with milk production; in fish it is thought to be related to the control of water and salt balance. Prolactin also acts in a cytokine-like manner and as an important regulator of the immune system. It has important cell cycle-related functions as a growth-, differentiating- and anti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pseudopregnancy
In mammalian species, pseudopregnancy is a physical state whereby all the signs and symptoms of pregnancy are exhibited, with the exception of the presence of a fetus, creating a false pregnancy. The corpus luteum (the remains of an ovulated ovarian follicle) is responsible for the development of maternal behavior and lactation, which are mediated by the continued production of progesterone by the corpus luteum through some or all of pregnancy. In most species, the corpus luteum is degraded in the absence of a pregnancy. However, in some species, the corpus luteum may persist in the absence of pregnancy and cause "pseudopregnancy", in which the female will exhibit clinical signs of pregnancy. The mechanism is not well understood, but prolactin and it’s receptors are known to be involved in pseudopregnancy. The role of prolactin in maintaining pseudopregnancy is evident. For instance in the rodent, if chronic prolactin is administered the pseudopregnancy will continue, whereas t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adrenal Gland
The adrenal glands (also known as suprarenal glands) are endocrine glands that produce a variety of hormones including adrenaline and the steroids aldosterone and cortisol. They are found above the kidneys. Each gland has an outer cortex which produces steroid hormones and an inner medulla. The adrenal cortex itself is divided into three main zones: the zona glomerulosa, the zona fasciculata and the zona reticularis. The adrenal cortex produces three main types of steroid hormones: mineralocorticoids, glucocorticoids, and androgens. Mineralocorticoids (such as aldosterone) produced in the zona glomerulosa help in the regulation of blood pressure and electrolyte balance. The glucocorticoids cortisol and cortisone are synthesized in the zona fasciculata; their functions include the regulation of metabolism and immune system suppression. The innermost layer of the cortex, the zona reticularis, produces androgens that are converted to fully functional sex hormones in the gonads ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Menstrual Synchrony
Menstrual synchrony, also called the McClintock effect, or the Wellesley effect, is a contested process whereby women who begin living together in close proximity would experience their menstrual cycle onsets (the onset of menstruation or menses) becoming more synchronized together in time than when previously living apart. "For example, the distribution of onsets of seven female lifeguards was scattered at the beginning of the summer, but after 3 months spent together, the onset of all seven cycles fell within a 4-day period." Martha McClintock's 1971 paper, published in ''Nature (journal), Nature'', says that menstrual cycle synchronization happens when the menstrual cycle onsets of two or more women become closer together in time than they were several months earlier. After the initial studies, several papers were published reporting methodological flaws in studies reporting menstrual synchrony including McClintock's study. In addition, other studies were published that failed ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Whitten Effect
The Whitten effect is stimulation, by male pheromones, of synchronous estrus in a female population. Social signals, or social stimuli, have an effect on reproduction in all mammals. For certain female mice, the pheromones contained in the urine of male mice can be such stimuli, inducing synchronous estrus.Ochiogu, Izuchukwu S., Chike F. Oguejiofor, and Ambrose N. Nwagbo. "Males' Non-Enhancement of Bruce and Whitten Effects in Female Mice – Mus Musculus." Animal Research International 6 (2009): 1077-081. When the pheromones contained in the urine of male mice stimulate synchronous estrus in a population of female mice, it is known as the Whitten effect. This is a phenomenon observed by Wesley K. Whitten (1956, 1966, 1968), whereby male mouse pheromone-laden urine synchronizes the estrus cycle "among unisexually grouped females," and is an example of male-to-female pheromonal effects in mice, similar to the Bruce effect.Jemilio, Bozena, Scott Harvey, and Milos Novotny. "Promo ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endocrinology
Endocrinology (from '' endocrine'' + '' -ology'') is a branch of biology and medicine dealing with the endocrine system, its diseases, and its specific secretions known as hormones. It is also concerned with the integration of developmental events proliferation, growth, and differentiation, and the psychological or behavioral activities of metabolism, growth and development, tissue function, sleep, digestion, respiration, excretion, mood, stress, lactation, movement, reproduction, and sensory perception caused by hormones. Specializations include behavioral endocrinology and comparative endocrinology. The endocrine system consists of several glands, all in different parts of the body, that secrete hormones directly into the blood rather than into a duct system. Therefore, endocrine glands are regarded as ductless glands. Hormones have many different functions and modes of action; one hormone may have several effects on different target organs, and, conversely, one target orga ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ethology
Ethology is the scientific study of animal behaviour, usually with a focus on behaviour under natural conditions, and viewing behaviour as an evolutionarily adaptive trait. Behaviourism as a term also describes the scientific and objective study of animal behaviour, usually referring to measured responses to stimuli or to trained behavioural responses in a laboratory context, without a particular emphasis on evolutionary adaptivity. Throughout history, different naturalists have studied aspects of animal behaviour. Ethology has its scientific roots in the work of Charles Darwin and of American and German ornithologists of the late 19th and early 20th century, including Charles O. Whitman, Oskar Heinroth, and Wallace Craig. The modern discipline of ethology is generally considered to have begun during the 1930s with the work of Dutch biologist Nikolaas Tinbergen and Austrian biologists Konrad Lorenz and Karl von Frisch, the three recipients of the 1973 Nobel Prize in Phys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
