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Rostral Ventromedial Medulla
The rostral ventromedial medulla (RVM), or ventromedial nucleus of the spinal cord, is a group of neurons located close to the midline on the floor of the medulla oblongata (myelencephalon). The rostral ventromedial medulla sends descending inhibitory and excitatory fibers to the dorsal horn spinal cord neurons. There are 3 categories of neurons in the RVM: on-cells, off-cells, and neutral cells. They are characterized by their response to nociceptive input. Off-cells show a transitory decrease in firing rate right before a nociceptive reflex, and are theorized to be inhibitory. Activation of off-cells, either by morphine or by any other means, results in antinociception. On-cells show a burst of activity immediately preceding nociceptive input, and are theorized to be contributing to the excitatory drive. Neutral cells show no response to nociceptive input. Involvement in neuropathic pain Research has shown the RVM to be important in the maintenance of neuropathic pain. Abla ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Myelencephalon
The myelencephalon or afterbrain is the most posterior region of the embryonic hindbrain, from which the medulla oblongata develops. Development Neural tube to myelencephalon During fetal development, divisions of the neural tube that give rise to the hindbrain (rhombencephalon) and the other primary vesicles (forebrain and midbrain) occur at just 28 days after conception. With the exception of the midbrain, these primary vesicles undergo further differentiation at 5 weeks after conception to form the myelencephalon and the other secondary vesicles. Myelencephalon to medulla Final shape differentiation of the myelencephalon into the medulla oblongata can be observed at 20 weeks gestation.Carlson, Neil R. Foundations of Behavioral Neuroscience.63-65 Medulla oblongata The medulla oblongata is part of the brain stem that serves as the connection of the spinal cord to the brain. It is situated between the pons and the spinal cord. Function The medulla oblongata ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
5-HT7
The 5-HT7 receptor is a member of the GPCR superfamily of cell surface receptors and is activated by the neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) The 5-HT7 receptor is coupled to Gs (stimulates the production of the intracellular signaling molecule cAMP) and is expressed in a variety of human tissues, particularly in the brain, the gastrointestinal tract, and in various blood vessels. This receptor has been a drug development target for the treatment of several clinical disorders. The 5-HT7 receptor is encoded by the ''HTR7'' gene, which in humans is transcribed into 3 different splice variants. Function When the 5-HT7 receptor is activated by serotonin, it sets off a cascade of events starting with release of the stimulatory G protein Gs from the GPCR complex. Gs in turn activates adenylate cyclase which increases intracellular levels of the second messenger cAMP. The 5-HT7 receptor plays a role in smooth muscle relaxation within the vasculature and in the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Mustard Oil
Mustard oil can mean either the pressed oil used for cooking, or a pungent essential oil also known as volatile oil of mustard. The essential oil results from grinding mustard seed, mixing the grounds with water, and extracting the resulting volatile oil by distillation. It can also be produced by dry distillation of the seed. Pressed mustard oil is used as cooking oil in some cultures, but sale is restricted in some countries due to high levels of erucic acid. Varieties of mustard seed also exist that are low in erucic acid. Pressed oil Oil makes up about 30% of mustard seeds. It can be produced from black mustard (''Brassica nigra''), brown mustard ('' B. juncea''), and white mustard ('' B. alba''). Having a distinctive pungent taste, the oil is used for cooking in India, Pakistan, Nepal and Bangladesh. Its pungent flavor is due to allyl isothiocyanate, a phytochemical of plants in the mustard family, Brassicaceae (for example, cabbage, horseradish or wasabi). Mustard oil ha ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Capsaicin
Capsaicin (8-methyl-''N''-vanillyl-6-nonenamide) ( or ) is an active component of chili peppers, which are plants belonging to the genus ''Capsicum''. It is a chemical irritant for mammals, including humans, and produces a sensation of burning in any tissue with which it comes into contact. Capsaicin and several related alkaloids are called capsaicinoids and are produced as secondary metabolites by chili peppers, probably as deterrents against certain mammals and fungi.What Made Chili Peppers So Spicy? Talk of the Nation, 15 August 2008. Pure capsaicin is a , colorless, highly |
Freund's Adjuvant
Freund's adjuvant is a solution of antigen emulsified in mineral oil and used as an immunopotentiator (booster). The complete form, Freund's Complete Adjuvant (FCA or CFA) is composed of inactivated and dried mycobacteria (usually '' M. tuberculosis''), whereas the incomplete form (FIA or IFA) lacks the mycobacterial components (hence just the water in oil emulsion). It is named after Jules T. Freund. Regulation Freund's complete adjuvant is effective in stimulating cell-mediated immunity and leads to potentiation of T helper cells that leads to the production of certain immunoglobulins and effector T cells. Its use in humans is forbidden by regulatory authorities, due to its toxicity. Even for animal research there are currently guidelines associated with its use, due to its painful reaction and potential for tissue damage. Injections of FCA should be subcutaneous or intraperitoneal, because intradermal injections may cause skin ulceration and necrosis; intramuscular injections m ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Substance P
Substance P (SP) is an undecapeptide (a peptide composed of a chain of 11 amino acid residues) and a member of the tachykinin neuropeptide family. It is a neuropeptide, acting as a neurotransmitter and as a neuromodulator. Substance P and its closely related neurokinin A (NKA) are produced from a polyprotein precursor after differential splicing of the preprotachykinin A gene. The deduced amino acid sequence of substance P is as follows: * Arg Pro Lys Pro Gln Gln Phe Phe Gly Leu Met (RPKPQQFFGLM) with an amidation at the C-terminus. Substance P is released from the terminals of specific sensory nerves. It is found in the brain and spinal cord and is associated with inflammatory processes and pain. Discovery The original discovery of Substance P (SP) was in 1931 by Ulf von Euler and John H. Gaddum as a tissue extract that caused intestinal contraction ''in vitro''. Its tissue distribution and biologic actions were further investigated over the following decades. The ele ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurokinin 1 Receptor
The tachykinin receptor 1 (TACR1) also known as neurokinin 1 receptor (NK1R) or substance P receptor (SPR) is a G protein coupled receptor found in the central nervous system and peripheral nervous system. The endogenous ligand for this receptor is Substance P, although it has some affinity for other tachykinins. The protein is the product of the ''TACR1'' gene. Properties Tachykinins are a family of neuropeptides that share the same hydrophobic C-terminal region with the amino acid sequence Phe-X-Gly- Leu- Met-NH2, where X represents a hydrophobic residue that is either an aromatic or a beta-branched aliphatic. The N-terminal region varies between different tachykinins. The term tachykinin originates in the rapid onset of action caused by the peptides in smooth muscles. Substance P (SP) is the most researched and potent member of the tachykinin family. It is an undecapeptide with the amino acid sequence Arg-Pro- Lys-Pro- Gln- Gln- Phe- Phe-Gly- Leu- Met-NH2. SP binds to all t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Alpha-2 Adrenergic Receptor
The alpha-2 (α2) adrenergic receptor (or adrenoceptor) is a G protein-coupled receptor (GPCR) associated with the Gi heterotrimeric G-protein. It consists of three highly homologous subtypes, including α2A-, α2B-, and α2C-adrenergic. Some species other than humans express a fourth α2D-adrenergic receptor as well. Catecholamines like norepinephrine (noradrenaline) and epinephrine (adrenaline) signal through the α2-adrenergic receptor in the central and peripheral nervous systems. Cellular localization The α2A adrenergic receptor is localised in the following central nervous system (CNS) structures: * Brainstem (especially the locus coeruleus) * Midbrain * Hypothalamus * Hippocampus * Spinal cord * Cerebral cortex * Cerebellum * Septum Whereas the α2B adrenergic receptor is localised in the following CNS structures: * Olfactory system * Thalamus * Pyramidal layer of the hippocampus * Cerebellar Purkinje layer and the α2C adrenergic receptor is localised in the CN ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve Injury
Nerve injury is an injury to nervous tissue. There is no single classification system that can describe all the many variations of nerve injuries. In 1941, Seddon introduced a classification of nerve injuries based on three main types of nerve fiber injury and whether there is continuity of the nerve. Usually, however, peripheral nerve injuries are classified in five stages, based on the extent of damage to both the nerve and the surrounding connective tissue, since supporting glial cells may be involved. Unlike in the central nervous system, neuroregeneration in the peripheral nervous system is possible. The processes that occur in peripheral regeneration can be divided into the following major events: Wallerian degeneration, axon regeneration/growth, and reinnervation of nervous tissue. The events that occur in peripheral regeneration occur with respect to the axis of the nerve injury. The proximal stump refers to the end of the injured neuron that is still attached to the ne ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nociception
Nociception (also nocioception, from Latin ''nocere'' 'to harm or hurt') is the sensory nervous system's process of encoding noxious stimuli. It deals with a series of events and processes required for an organism to receive a painful stimulus, convert it to a molecular signal, and recognize and characterize the signal in order to trigger an appropriate defense response. In nociception, intense chemical (e.g., capsaicin present in Chili pepper or Cayenne pepper), mechanical (e.g., cutting, crushing), or thermal (heat and cold) stimulation of sensory neurons called nociceptors produces a signal that travels along a chain of nerve fibers via the spinal cord to the brain. Nociception triggers a variety of physiological and behavioral responses to protect the organism against an aggression and usually results in a subjective experience, or perception, of pain in sentient beings. Detection of noxious stimuli Potentially damaging mechanical, thermal, and chemical stimuli are detected ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Allodynia
Allodynia is a condition in which pain is caused by a stimulus that does not normally elicit pain. For example, bad sunburn can cause temporary allodynia, and touching sunburned skin, or running cold or warm water over it, can be very painful. It is different from hyperalgesia, an exaggerated response from a normally painful stimulus. The term is from Ancient Greek '' άλλος'' ''állos'' "other" and '' οδύνη'' ''odúnē'' "pain". Types There are different kinds or types of allodynia: * Mechanical allodynia (also known as tactile allodynia) ** Static mechanical allodynia – pain in response when touched ** Dynamic mechanical allodynia – pain in response to stroking lightly * Thermal (hot or cold) allodynia – pain from normally mild skin temperatures in the affected area * Movement allodynia – pain triggered by normal movement of joints or muscles Causes Allodynia is a clinical feature of many painful conditions, such as neuropathies,Landerholm, A. (2010). Neuropathic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Intrathecal
Intrathecal administration is a route of administration for drugs via an injection into the spinal canal, or into the subarachnoid space so that it reaches the cerebrospinal fluid (CSF) and is useful in spinal anesthesia, chemotherapy, or pain management applications. This route is also used to introduce drugs that fight certain infections, particularly post-neurosurgical. The drug needs to be given this way to avoid being stopped by the blood–brain barrier. The same drug given orally must enter the blood stream and may not be able to pass out and into the brain. Drugs given by the intrathecal route often have to be compounded specially by a pharmacist or technician because they cannot contain any preservative or other potentially harmful inactive ingredients that are sometimes found in standard injectable drug preparations. The route of administration is sometimes simply referred to as "intrathecal"; however, the term is also an adjective that refers to something occurring in or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
