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Neurotrophic
Neurotrophic factors (NTFs) are a family of biomolecules – nearly all of which are peptides or small proteins – that support the growth, survival, and differentiation of both developing and mature neurons. Most NTFs exert their trophic effects on neurons by signaling through tyrosine kinases, usually a receptor tyrosine kinase. In the mature nervous system, they promote neuronal survival, induce synaptic plasticity, and modulate the formation of long-term memories. Neurotrophic factors also promote the initial growth and development of neurons in the central nervous system and peripheral nervous system, and they are capable of regrowing damaged neurons in test tubes and animal models. Some neurotrophic factors are also released by the target tissue in order to guide the growth of developing axons. Most neurotrophic factors belong to one of three families: (1) neurotrophins, (2) glial cell-line derived neurotrophic factor family ligands (GFLs), and (3) neuropoietic cy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Brain-derived Neurotrophic Factor
Brain-derived neurotrophic factor (BDNF), or abrineurin, is a protein found in the and the periphery. that, in humans, is encoded by the ''BDNF'' gene. BDNF is a member of the neurotrophin family of growth factors, which are related to the canonical nerve growth factor (NGF), a family which also includes NT-3 and NT-4/NT-5. Neurotrophic factors are found in the brain and the periphery. BDNF was first isolated from a pig brain in 1982 by Yves-Alain Barde and Hans Thoenen. BDNF activates the TrkB tyrosine kinase receptor. Function BDNF acts on certain neurons of the central nervous system and the peripheral nervous system expressing TrkB, helping to support survival of existing neurons, and encouraging growth and differentiation of new neurons and synapses. In the brain it is active in the hippocampus, cortex, and basal forebrain—areas vital to learning, memory, and higher thinking. BDNF is also expressed in the retina, kidneys, prostate, motor neurons, and skeletal musc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropomyosin Receptor Kinase B
Tropomyosin receptor kinase B (TrkB), also known as tyrosine receptor kinase B, or BDNF/NT-3 growth factors receptor or neurotrophic tyrosine kinase, receptor, type 2 is a protein that in humans is encoded by the ''NTRK2'' gene. TrkB is a receptor for brain-derived neurotrophic factor (BDNF). Standard pronunciation is "track bee". Function Tropomyosin receptor kinase B is the high affinity catalytic receptor for several " neurotrophins", which are small protein growth factors that induce the survival and differentiation of distinct cell populations. The neurotrophins that activate TrkB are: BDNF (Brain Derived Neurotrophic Factor), neurotrophin-4 (NT-4), and neurotrophin-3 (NT-3).> As such, TrkB mediates the multiple effects of these neurotrophic factors, which includes neuronal differentiation and survival. Research has shown that activation of the TrkB receptor can lead to down regulation of the KCC2 chloride transporter in cells of the CNS. Except for the role of the pathw ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotrophins
Neurotrophins are a family of proteins that induce the survival, development, and function of neurons. They belong to a class of growth factors, secreted proteins that can signal particular cells to survive, differentiate, or grow. Growth factors such as neurotrophins that promote the survival of neurons are known as neurotrophic factors. Neurotrophic factors are secreted by target tissue and act by preventing the associated neuron from initiating programmed cell death – allowing the neurons to survive. Neurotrophins also induce differentiation of progenitor cells, to ''form'' neurons. Although the vast majority of neurons in the mammalian brain are formed prenatally, parts of the adult brain (for example, the hippocampus) retain the ability to grow new neurons from neural stem cells, a process known as neurogenesis. Neurotrophins are chemicals that help to stimulate and control neurogenesis. Terminology According to the United States National Library of Medicine's medical sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tropomyosin Receptor Kinase A
Tropomyosin receptor kinase A (TrkA), also known as high affinity nerve growth factor receptor, neurotrophic tyrosine kinase receptor type 1, or TRK1-transforming tyrosine kinase protein is a protein that in humans is encoded by the ''NTRK1'' gene. This gene encodes a member of the neurotrophic tyrosine kinase receptor (NTKR) family. This kinase is a membrane-bound receptor that, upon neurotrophin binding, phosphorylates itself (autophosphorylation) and members of the MAPK pathway. The presence of this kinase leads to cell differentiation and may play a role in specifying sensory neuron subtypes. Mutations in this gene have been associated with congenital insensitivity to pain with anhidrosis, self-mutilating behaviors, intellectual disability and/or cognitive impairment and certain cancers. Alternate transcriptional splice variants of this gene have been found, but only three have been characterized to date. Function and Interaction with NGF TrkA is the high affinity cataly ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
GDNF Family Of Ligands
The GDNF family of ligands (GFL) consists of four neurotrophic factors: glial cell line-derived neurotrophic factor (GDNF), neurturin (NRTN), artemin (ARTN), and persephin (PSPN). GFLs have been shown to play a role in a number of biological processes including cell survival, neurite outgrowth, cell differentiation and cell migration. In particular signalling by GDNF promotes the survival of dopaminergic neurons. Signalling complex formation At the cell surface of target cells, a signalling complex forms, composed of a particular GFL dimer, a receptor tyrosine kinase molecule RET, and a cell surface-bound co-receptor that is a member of the GFRα protein family. The primary ligands for the co-receptors GFRα1, GFRα2, GFRα3, and GFRα4 are GDNF, NRTN, ARTN, and PSPN, respectively. Upon initial GFL-GFRα complex formation, the complex then brings together two molecules of RET, triggering trans-autophosphorylation of specific tyrosine residues within the tyrosine kinase domain o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Glial Cell-line Derived Neurotrophic Factor Family Ligands
The GDNF family of ligands (GFL) consists of four neurotrophic factors: glial cell line-derived neurotrophic factor (GDNF), neurturin (NRTN), artemin (ARTN), and persephin (PSPN). GFLs have been shown to play a role in a number of biological processes including cell survival, neurite outgrowth, cell differentiation and cell migration. In particular signalling by GDNF promotes the survival of dopaminergic neurons. Signalling complex formation At the cell surface of target cells, a signalling complex forms, composed of a particular GFL dimer, a receptor tyrosine kinase molecule RET, and a cell surface-bound co-receptor that is a member of the GFRα protein family. The primary ligands for the co-receptors GFRα1, GFRα2, GFRα3, and GFRα4 are GDNF, NRTN, ARTN, and PSPN, respectively. Upon initial GFL-GFRα complex formation, the complex then brings together two molecules of RET, triggering trans-autophosphorylation of specific tyrosine residues within the tyrosine kinase domain of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotrophin-4
Neurotrophin-4 (NT-4), also known as neurotrophin-5 (NT-5), is a protein that in humans is encoded by the ''NTF4'' gene. It is a neurotrophic factor that signals predominantly through the TrkB receptor tyrosine kinase Receptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase .... See also * Tropomyosin receptor kinase B § Agonists References Further reading * * * * * * * * * * * * * * * * * * * * External links * * Neurotrophic factors Peptide hormones Growth factors Developmental neuroscience Proteins TrkB agonists {{gene-19-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nerve Growth Factor
Nerve growth factor (NGF) is a neurotrophic factor and neuropeptide primarily involved in the regulation of growth, maintenance, proliferation, and survival of certain target neurons. It is perhaps the prototypical growth factor, in that it was one of the first to be described. Since it was first isolated by Nobel Laureates Rita Levi-Montalcini and Stanley Cohen in 1956, numerous biological processes involving NGF have been identified, two of them being the survival of pancreatic beta cells and the regulation of the immune system. Structure NGF is initially in a 7S, 130-kDa complex of 3 proteins – Alpha-NGF, Beta-NGF, and Gamma-NGF (2:1:2 ratio) when expressed. This form of NGF is also referred to as proNGF (NGF precursor). The gamma subunit of this complex acts as a serine protease, and cleaves the N-terminal of the beta subunit, thereby activating the protein into functional NGF. The term ''nerve growth factor'' usually refers to the 2.5S, 26-kDa beta subunit of the protein ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor Tyrosine Kinase
Receptor tyrosine kinases (RTKs) are the high-affinity cell surface receptors for many polypeptide growth factors, cytokines, and hormones. Of the 90 unique tyrosine kinase genes identified in the human genome, 58 encode receptor tyrosine kinase proteins. Receptor tyrosine kinases have been shown not only to be key regulators of normal cellular processes but also to have a critical role in the development and progression of many types of cancer. Mutations in receptor tyrosine kinases lead to activation of a series of signalling cascades which have numerous effects on protein expression. Receptor tyrosine kinases are part of the larger family of protein tyrosine kinases, encompassing the receptor tyrosine kinase proteins which contain a transmembrane domain, as well as the non-receptor tyrosine kinases which do not possess transmembrane domains. History The first RTKs to be discovered were EGF and NGF in the 1960s, but the classification of receptor tyrosine kinases was not d ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Major Depressive Disorder
Major depressive disorder (MDD), also known as clinical depression, is a mental disorder characterized by at least two weeks of pervasive low mood, low self-esteem, and loss of interest or pleasure in normally enjoyable activities. Introduced by a group of US clinicians in the mid-1970s, the term was adopted by the American Psychiatric Association for this symptom cluster under mood disorders in the 1980 version of the ''Diagnostic and Statistical Manual of Mental Disorders'' (DSM-III), and has become widely used since. The diagnosis of major depressive disorder is based on the person's reported experiences, behavior reported by relatives or friends, and a mental status examination. There is no laboratory test for the disorder, but testing may be done to rule out physical conditions that can cause similar symptoms. The most common time of onset is in a person's 20s, with females affected about twice as often as males. The course of the disorder varies widely, from one epis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Peptide
Peptides (, ) are short chains of amino acids linked by peptide bonds. Long chains of amino acids are called proteins. Chains of fewer than twenty amino acids are called oligopeptides, and include dipeptides, tripeptides, and tetrapeptides. A polypeptide is a longer, continuous, unbranched peptide chain. Hence, peptides fall under the broad chemical classes of biological polymers and oligomers, alongside nucleic acids, oligosaccharides, polysaccharides, and others. A polypeptide that contains more than approximately 50 amino acids is known as a protein. Proteins consist of one or more polypeptides arranged in a biologically functional way, often bound to ligands such as coenzymes and cofactors, or to another protein or other macromolecule such as DNA or RNA, or to complex macromolecular assemblies. Amino acids that have been incorporated into peptides are termed residues. A water molecule is released during formation of each amide bond.. All peptides except cyclic pep ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dorsal Root Ganglion
A dorsal root ganglion (or spinal ganglion; also known as a posterior root ganglion) is a cluster of neurons (a ganglion) in a dorsal root of a spinal nerve. The cell bodies of sensory neurons known as first-order neurons are located in the dorsal root ganglia. The axons of dorsal root ganglion neurons are known as afferents. In the peripheral nervous system, afferents refer to the axons that relay sensory information into the central nervous system (i.e. the brain and the spinal cord). Structure The neurons comprising the dorsal root ganglion are of the pseudo-unipolar type, meaning they have a cell body (soma) with two branches that act as a single axon, often referred to as a ''distal process'' and a ''proximal process''. Unlike the majority of neurons found in the central nervous system, an action potential in posterior root ganglion neuron may initiate in the ''distal process'' in the periphery, bypass the cell body, and continue to propagate along the ''proximal process ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
