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Ventrobasal Complex
The ventrobasal complex (VB) is a relay nucleus of the thalamus for nociceptive stimuli received from nociceptive nerves. The VB consists of the ventral posteromedial nucleus (VPM) and the ventral posterolateral nucleus (VPL). In some species the ventral posterolateral nucleus, pars caudalis is also a part of the VB.Natsu Koyama, Yasuo Nishikawa, Toshikatsu Yokota. Distribution of nociceptive neurons in the ventrobasal complex of macaque thalamus. Neuroscience Research 31 (1998) 39-51. The VB gets inputs from the spinothalamic tract, medial lemniscus, and corticothalamic tract.W.D. Willis Jr. et al. Projections from the marginal zone and deep dorsal horn to the ventrobasal nuclei of the primate thalamus. Pain 92 (2001) 267-276.Yasuyuki Nagumo, Yuichi Takeuchi, Keiji Imoto, Mariko Miyata. Synapse- and subtype-specific modulation of synaptic transmission by nicotinic acetylcholine receptors in the ventrobasal thalamus. Neuroscience Research 69 (2011) 203-213. The main output of the VB ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thalamus
The thalamus (from Greek θάλαμος, "chamber") is a large mass of gray matter located in the dorsal part of the diencephalon (a division of the forebrain). Nerve fibers project out of the thalamus to the cerebral cortex in all directions, allowing hub-like exchanges of information. It has several functions, such as the relaying of sensory signals, including motor signals to the cerebral cortex and the regulation of consciousness, sleep, and alertness. Anatomically, it is a paramedian symmetrical structure of two halves (left and right), within the vertebrate brain, situated between the cerebral cortex and the midbrain. It forms during embryonic development as the main product of the diencephalon, as first recognized by the Swiss embryologist and anatomist Wilhelm His Sr. in 1893. Anatomy The thalamus is a paired structure of gray matter located in the forebrain which is superior to the midbrain, near the center of the brain, with nerve fibers projecting out to the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Acetylcholine
Acetylcholine (ACh) is an organic chemical that functions in the brain and body of many types of animals (including humans) as a neurotransmitter. Its name is derived from its chemical structure: it is an ester of acetic acid and choline. Parts in the body that use or are affected by acetylcholine are referred to as cholinergic. Substances that increase or decrease the overall activity of the cholinergic system are called cholinergics and anticholinergics, respectively. Acetylcholine is the neurotransmitter used at the neuromuscular junction—in other words, it is the chemical that motor neurons of the nervous system release in order to activate muscles. This property means that drugs that affect cholinergic systems can have very dangerous effects ranging from paralysis to convulsions. Acetylcholine is also a neurotransmitter in the autonomic nervous system, both as an internal transmitter for the sympathetic nervous system and as the final product released by the parasymp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Baclofen
Baclofen, sold under the brand name Lioresal among others, is a medication used to treat muscle spasticity such as from a spinal cord injury or multiple sclerosis. It may also be used for hiccups and muscle spasms near the end of life. It is taken by mouth or by delivery into the spinal canal. Common side effects include sleepiness, weakness, and dizziness. Serious side effects may occur if baclofen is rapidly stopped including seizures and rhabdomyolysis. Use in pregnancy is of unclear safety while use during breastfeeding is probably safe. It is believed to work by decreasing levels of certain neurotransmitters. Baclofen was approved for medical use in the United States in 1977. It is available as a generic medication. In 2020, it was the 108th most commonly prescribed medication in the United States, with more than 6million prescriptions. Medical uses Baclofen is primarily used for the treatment of spastic movement disorders, especially in instances of spinal cord inju ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Inhibitory Postsynaptic Potential
An inhibitory postsynaptic potential (IPSP) is a kind of synaptic potential that makes a postsynaptic neuron less likely to generate an action potential.Purves et al. Neuroscience. 4th ed. Sunderland (MA): Sinauer Associates, Incorporated; 2008. IPSP were first investigated in motorneurons by David P. C. Lloyd, John Eccles and Rodolfo Llinás in the 1950s and 1960s. The opposite of an inhibitory postsynaptic potential is an excitatory postsynaptic potential (EPSP), which is a synaptic potential that makes a postsynaptic neuron ''more'' likely to generate an action potential. IPSPs can take place at all chemical synapses, which use the secretion of neurotransmitters to create cell to cell signalling. Inhibitory presynaptic neurons release neurotransmitters that then bind to the postsynaptic receptors; this induces a change in the permeability of the postsynaptic neuronal membrane to particular ions. An electric current that changes the postsynaptic membrane potential to create ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GABAB Receptor
GABAB receptors (GABABR) are G-protein coupled receptors for gamma-aminobutyric acid (GABA), therefore making them metabotropic receptors, that are linked via G-proteins to potassium channels. The changing potassium concentrations hyperpolarize the cell at the end of an action potential. The reversal potential of the GABAB-mediated IPSP (inhibitory postsynaptic potential) is –100 mV, which is much more hyperpolarized than the GABAA IPSP. GABAB receptors are found in the central nervous system and the autonomic division of the peripheral nervous system. The receptors were first named in 1981 when their distribution in the CNS was determined, which was determined by Norman Bowery and his team using radioactively labelled baclofen. Functions GABABRs stimulate the opening of K+ channels, specifically GIRKs, which brings the neuron closer to the equilibrium potential of K+. This reduces the frequency of action potentials which reduces neurotransmitter release. Thus GABAB r ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
DAMGO
DAMGO ( D-Ala2,_''N''-MePhe4,_Gly-ol.html" ;"title="small>D-Ala2, ''N''-MePhe4, Gly-ol">small>D-Ala2, ''N''-MePhe4, Gly-olenkephalin) is a synthetic opioid peptide with high μ-opioid receptor specificity. It was synthesized as a biologically stable analog of δ-opioid receptor-preferring endogenous opioids, leu- and met-enkephalin. Structures of DAMGO bound to the µ opioid receptor reveal a very similar binding pose to morphinans. Its structure is H-Tyr-D-Ala-Gly-''N''-MePhe-Gly-ol. DAMGO has been used in experimental settings for the possibility of alleviating or reducing opiate tolerance for patients under the treatment of an opioid. Such treatment on rats, adding DAMGO to morphine administration, showed that after seven days morphine had as much of an effect at the same dosage as the first day when administered together with DAMGO to the rats, whereas a separate control group of rats that were administered the same dosage of morphine over the course of the same week, but wit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Μ-opioid Receptor
The μ-opioid receptors (MOR) are a class of opioid receptors with a high affinity for enkephalins and beta-endorphin, but a low affinity for dynorphins. They are also referred to as μ(''mu'')-opioid peptide (MOP) receptors. The prototypical μ-opioid receptor agonist is morphine, the primary psychoactive alkaloid in opium. It is an inhibitory G-protein coupled receptor that activates the Gi alpha subunit, inhibiting adenylate cyclase activity, lowering cAMP levels. Structure The structure of the μ-opioid receptor has been determined with the antagonist β-FNA, the agonist BU72, and in a complex with DAMGO and Gi protein. Splice variants Three variants of the μ-opioid receptor are well characterized, though RT-PCR has identified up to 10 total splice variants in humans. Location They can exist either presynaptically or postsynaptically depending upon cell types. The μ-opioid receptors exist mostly presynaptically in the periaqueductal gray region, and in the superfi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nicotinic Acetylcholine Receptor
Nicotinic acetylcholine receptors, or nAChRs, are receptor polypeptides that respond to the neurotransmitter acetylcholine. Nicotinic receptors also respond to drugs such as the agonist nicotine. They are found in the central and peripheral nervous system, muscle, and many other tissues of many organisms. At the neuromuscular junction they are the primary receptor in muscle for motor nerve-muscle communication that controls muscle contraction. In the peripheral nervous system: (1) they transmit outgoing signals from the presynaptic to the postsynaptic cells within the sympathetic and parasympathetic nervous system, and (2) they are the receptors found on skeletal muscle that receive acetylcholine released to signal for muscular contraction. In the immune system, nAChRs regulate inflammatory processes and signal through distinct intracellular pathways. In insects, the cholinergic system is limited to the central nervous system. The nicotinic receptors are considered cholinergi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Wide Dynamic Range Neuron
The wide dynamic range (WDR) neuron was first discovered by Mendell in 1966. Early studies of this neuron established what is known as the gate control theory of pain. The basic concept is that non-painful stimuli block the pathways for painful stimuli, inhibiting possible painful responses. This theory was supported by the fact that WDR neurons are responsible for responses to both painful and non-painful stimuli, and the idea that these neurons couldn't produce more than one of these responses simultaneously. WDR neurons respond to all types of somatosensory stimuli, make up the majority of the neurons found in the posterior grey column, and have the ability to produce long range responses including those responsible for pain and itch. Anatomy and physiology WDR neurons are found in the posterior grey column of the spinal cord. This area of the spinal cord houses two different types of neurons involved in the process of pain: WDR neurons and nociceptive specific neurons (NS). A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Posterior Horn Of Spinal Cord
The posterior grey column (posterior cornu, dorsal horn, spinal dorsal horn, posterior horn, sensory horn) of the spinal cord is one of the three grey columns of the spinal cord. It receives several types of sensory information from the body, including fine touch, proprioception, and vibration. This information is sent from receptors of the skin, bones, and joints through sensory neurons whose cell bodies lie in the dorsal root ganglion. Anatomy The posterior grey column is subdivided into six layers termed Rexed laminae I-VI *Marginal nucleus of spinal cord (lamina I) *Substantia gelatinosa of Rolando (lamina II) *Nucleus proprius (laminae III, IV) *Spinal lamina V, the neck of the posterior horn *Spinal lamina VI, the base of the posterior horn. The other four Rexed laminae are located in the other two grey columns in the spinal cord. Additional images File:Gray687.png, Section of the medulla oblongata through the lower part of the decussation of the pyramids See also * ... [...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] |
Spinal Cord
The spinal cord is a long, thin, tubular structure made up of nervous tissue, which extends from the medulla oblongata in the brainstem to the lumbar region of the vertebral column (backbone). The backbone encloses the central canal of the spinal cord, which contains cerebrospinal fluid. The brain and spinal cord together make up the central nervous system (CNS). In humans, the spinal cord begins at the occipital bone, passing through the foramen magnum and then enters the spinal canal at the beginning of the cervical vertebrae. The spinal cord extends down to between the first and second lumbar vertebrae, where it ends. The enclosing bony vertebral column protects the relatively shorter spinal cord. It is around long in adult men and around long in adult women. The diameter of the spinal cord ranges from in the cervical and lumbar regions to in the thoracic area. The spinal cord functions primarily in the transmission of nerve signals from the motor cortex to the body, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
