Reuptake is the reabsorption of a neurotransmitter by a neurotransmitter transporter located along the plasma membrane of an axon terminal or glial cell after it has performed its function of transmitting a neural impulse.
Astrocytes, also known collectively as astroglia, are characteristic star-shaped glial cells in the brain and spinal cord. They perform many functions, including biochemical control of endothelial cells that form the blood–brain barrier, provision of nutrients to the nervous tissue, maintenance of extracellular ion balance, regulation of cerebral blood flow, and a role in the repair and scarring process of the brain and spinal cord following infection and traumatic injuries. The proportion of astrocytes in the brain is not well defined; depending on the counting technique used, studies have found that the astrocyte proportion varies by region and ranges from 20% to around 40% of all glia. Another study reports that astrocytes are the most numerous cell type in the brain. Astrocytes are the major source of cholesterol in the central nervous system. Apolipoprotein E transports cholesterol from astrocytes to neurons and other glial cells, regulating cell signaling in the brain. Astrocytes in humans are more than twenty times larger than in rodent brains, and make contact with more than ten times the number of synapses.
Theanine, also known as L-γ-glutamylethylamide and N5-ethyl-L-glutamine, is an amino acid analogue of the proteinogenic amino acids L-glutamate and L-glutamine and is found primarily in particular plant and fungal species. It was discovered as a constituent of green tea in 1949; in 1950, it was isolated from gyokuro leaves. Theanine provides a unique brothy or savory (umami) flavor to green tea infusions.
Glutamate transporters are a family of neurotransmitter transporter proteins that move glutamate – the principal excitatory neurotransmitter – across a membrane. The family of glutamate transporters is composed of two primary subclasses: the excitatory amino acid transporter (EAAT) family and vesicular glutamate transporter (VGLUT) family. In the brain, EAATs remove glutamate from the synaptic cleft and extrasynaptic sites via glutamate reuptake into glial cells and neurons, while VGLUTs move glutamate from the cell cytoplasm into synaptic vesicles. Glutamate transporters also transport aspartate and are present in virtually all peripheral tissues, including the heart, liver, testes, and bone. They exhibit stereoselectivity for L-glutamate but transport both L-aspartate and D-aspartate.
Excitatory amino-acid transporter 5 (EAAT5) is a protein that in humans is encoded by the SLC1A7 gene.
Excitatory amino-acid transporter 4 (EAAT4) is a protein that in humans is encoded by the SLC1A6 gene.
Satellite glial cells, formerly called amphicytes, are glial cells that cover the surface of neuron cell bodies in ganglia of the peripheral nervous system. Thus, they are found in sensory, sympathetic, and parasympathetic ganglia. Both satellite glial cells (SGCs) and Schwann cells are derived from the neural crest of the embryo during development. SGCs have been found to play a variety of roles, including control over the microenvironment of sympathetic ganglia. They are thought to have a similar role to astrocytes in the central nervous system (CNS). They supply nutrients to the surrounding neurons and also have some structural function. Satellite cells also act as protective, cushioning cells. Additionally, they express a variety of receptors that allow for a range of interactions with neuroactive chemicals. Many of these receptors and other ion channels have recently been implicated in health issues including chronic pain and herpes simplex. There is much more to be learned about these cells, and research surrounding additional properties and roles of the SGCs is ongoing.
Neurotransmitter transporters are a class of membrane transport proteins that span the cellular membranes of neurons. Their primary function is to carry neurotransmitters across these membranes and to direct their further transport to specific intracellular locations. There are more than twenty types of neurotransmitter transporters.
Excitatory amino acid transporter 1 (EAAT1) is a protein that, in humans, is encoded by the SLC1A3 gene. EAAT1 is also often called the GLutamate ASpartate Transporter 1 (GLAST-1).
Maslinic acid is a compound derived from dry olive-pomace oil which is a byproduct of olive oil extraction. It is a member of the group of triterpenes known as oleananes.
Excitatory amino acid transporter 2 (EAAT2) also known as solute carrier family 1 member 2 (SLC1A2) and glutamate transporter 1 (GLT-1) is a protein that in humans is encoded by the SLC1A2 gene. Alternatively spliced transcript variants of this gene have been described, but their full-length nature is not known.
Excitatory amino acid transporter 3 (EAAT3), is a protein that in humans is encoded by the SLC1A1 gene.
Cystine/glutamate transporter is an antiporter that in humans is encoded by the SLC7A11 gene.
Neutral amino acid transporter A is a protein that in humans is encoded by the SLC1A4 gene.
GABA transporters (Gamma-Aminobutyric acid transporters) belong to the family of neurotransmitters known as sodium symporters, also known as solute carrier 6 (SLC6). These are large family of neurotransmitter which are Na+ concentration dependent. They are found in various regions of the brain in different cell types, such as neurons and astrocytes.
WAY-213,613 is a drug which acts as a reuptake inhibitor for the glutamate transporter subtype EAAT2, selective over other glutamate transporter subtypes and highly selective over metabotropic and ionotropic glutamate receptors. It is used in scientific research into the function of the glutamate transporters.
The sodium/glutamate symporter, also known as glutamate permease, is a transmembrane protein family found in bacteria and archaea. These proteins are symporters that are responsible for the sodium-dependent uptake of extracellular glutamate into the cell. They are integral membrane proteins located in the bacterial inner membrane. The best-studied member of the family is GltS from Escherichia coli. GltS contains ten transmembrane helices arranged in two antiparallel 5-helix domains and functions as a homodimer. Substrates for GltS include L- and D-glutamate, as well as toxic analogs α-methylglutamate, and homocysteate. In studies of E. coli growth, bacteria without GltS were unable to grow in a medium where glutamate is the only source of carbon.
An excitatory amino acid reuptake inhibitor (EAARI) is a type of drug which inhibits the reuptake of the excitatory neurotransmitters glutamate and aspartate by blocking one or more of the excitatory amino acid transporters (EAATs).
Ralph W. Kuncl is an American neurologist and president emeritus of the University of Redlands.
The gltS RNA motif is a conserved RNA structure that was discovered by bioinformatics. gltS motifs are found in the bacterial lineage Vibrionaceae.
