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Dopamine Transporter
The dopamine transporter (also dopamine active transporter, DAT, SLC6A3) is a membrane-spanning protein that pumps the neurotransmitter dopamine out of the synaptic cleft back into cytosol. In the cytosol, other transporters sequester the dopamine into vesicles for storage and later release. Dopamine reuptake via DAT provides the primary mechanism through which dopamine is cleared from synapses, although there may be an exception in the prefrontal cortex, where evidence points to a possibly larger role of the norepinephrine transporter. DAT is implicated in a number of dopamine-related disorders, including attention deficit hyperactivity disorder, bipolar disorder, clinical depression, alcoholism, eating disorders, and substance use disorder. The gene that encodes the DAT protein is located on human chromosome 5, consists of 15 coding exons, and is roughly 64 kbp long. Evidence for the associations between DAT and dopamine related disorders has come from a type of geneti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotransmitter
A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, any main body part or target cell, may be another neuron, but could also be a gland or muscle cell. Neurotransmitters are released from synaptic vesicles into the synaptic cleft where they are able to interact with neurotransmitter receptors on the target cell. The neurotransmitter's effect on the target cell is determined by the receptor it binds. Many neurotransmitters are synthesized from simple and plentiful precursors such as amino acids, which are readily available and often require a small number of biosynthetic steps for conversion. Neurotransmitters are essential to the function of complex neural systems. The exact number of unique neurotransmitters in humans is unknown, but more than 100 have been identified. Common neurotransmitters include glutamate, GABA, acetylcholine, glycine and norepinephrine. Mechanism and cycle ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
VNTR
A variable number tandem repeat (or VNTR) is a location in a genome where a short nucleotide sequence is organized as a tandem repeat. These can be found on many chromosomes, and often show variations in length (number of repeats) among individuals. Each variant acts as an inherited allele, allowing them to be used for personal or parental identification. Their analysis is useful in genetics and biology research, forensics, and DNA fingerprinting. Structure and allelic variation In the schematic above, the rectangular blocks represent each of the repeated DNA sequences at a particular VNTR location. The repeats are in tandem – i.e. they are clustered together and oriented in the same direction. Individual repeats can be removed from (or added to) the VNTR via recombination or replication errors, leading to alleles with different numbers of repeats. Flanking regions are segments of non-repetitive sequence (shown here as thin lines), allowing the VNTR blocks to be ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Voltage-gated Calcium Channels
Voltage-gated calcium channels (VGCCs), also known as voltage-dependent calcium channels (VDCCs), are a group of voltage-gated ion channels found in the membrane of excitable cells (''e.g.'', muscle, glial cells, neurons, etc.) with a permeability to the calcium ion Ca2+. These channels are slightly permeable to sodium ions, so they are also called Ca2+-Na+ channels, but their permeability to calcium is about 1000-fold greater than to sodium under normal physiological conditions. At physiologic or resting membrane potential, VGCCs are normally closed. They are activated (''i.e.'': opened) at depolarized membrane potentials and this is the source of the "voltage-gated" epithet. The concentration of calcium (Ca2+ ions) is normally several thousand times higher outside the cell than inside. Activation of particular VGCCs allows a Ca2+ influx into the cell, which, depending on the cell type, results in activation of calcium-sensitive potassium channels, muscular contraction, e ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Membrane Potential
Membrane potential (also transmembrane potential or membrane voltage) is the difference in electric potential between the interior and the exterior of a biological cell. That is, there is a difference in the energy required for electric charges to move from the internal to exterior cellular environments and vice versa, as long as there is no acquisition of kinetic energy or the production of radiation. The concentration gradients of the charges directly determine this energy requirement. For the exterior of the cell, typical values of membrane potential, normally given in units of milli volts and denoted as mV, range from –80 mV to –40 mV. All animal cells are surrounded by a membrane composed of a lipid bilayer with proteins embedded in it. The membrane serves as both an insulator and a diffusion barrier to the movement of ions. Transmembrane proteins, also known as ion transporter or ion pump proteins, actively push ions across the membrane and establish concentratio ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radioactive Tracer
A radioactive tracer, radiotracer, or radioactive label is a chemical compound in which one or more atoms have been replaced by a radionuclide so by virtue of its radioactive decay it can be used to explore the mechanism of chemical reactions by tracing the path that the radioisotope follows from reactants to products. Radiolabeling or radiotracing is thus the radioactive form of isotopic labeling. In biological contexts, use of radioisotope tracers are sometimes called radioisotope feeding experiments. Radioisotopes of hydrogen, carbon, phosphorus, sulfur, and iodine have been used extensively to trace the path of biochemical reactions. A radioactive tracer can also be used to track the distribution of a substance within a natural system such as a cell or tissue, or as a flow tracer to track fluid flow. Radioactive tracers are also used to determine the location of fractures created by hydraulic fracturing in natural gas production.Reis, John C. (1976). ''Environmental Cont ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Electrophysiology
Electrophysiology (from Ancient Greek, Greek , ''ēlektron'', "amber" [see the Electron#Etymology, etymology of "electron"]; , ''physis'', "nature, origin"; and , ''-logy, -logia'') is the branch of physiology that studies the electrical properties of biological cell (biology), cells and tissues. It involves measurements of voltage changes or electric current or manipulations on a wide variety of scales from single ion channel proteins to whole organs like the heart. In neuroscience, it includes measurements of the electrical activity of neurons, and, in particular, action potential activity. Recordings of large-scale electric signals from the nervous system, such as electroencephalography, may also be referred to as electrophysiological recordings. They are useful for electrodiagnostic medicine, electrodiagnosis and monitoring (medicine), monitoring. Definition and scope Classical electrophysiological techniques Principle and mechanisms Electrophysiology is the branch of phys ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoamine Transporter
Monoamine transporters (MATs) are protein structures that function as integral plasma-membrane transporters to regulate concentrations of extracellular monoamine neurotransmitters. Three major classes of MATs (SERT, DAT, NET) are responsible for the reuptake of their associated amine neurotransmitters (serotonin, dopamine, norepinephrine). MATs are located just outside the synaptic cleft (peri-synaptically), transporting monoamine transmitter overflow from the synaptic cleft back to the cytoplasm of the pre-synaptic neuron. MAT regulation generally occurs through protein phosphorylation and posttranslational modification. Due to their significance in neuronal signaling, MATs are commonly associated with drugs used to treat mental disorders as well as recreational drugs. Compounds targeting MATs range from medications such as the wide variety of tricyclic antidepressants, selective serotonin reuptake inhibitors such as fluoxetine (Prozac) to stimulant medications such as methy ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Model
A model is an informative representation of an object, person or system. The term originally denoted the plans of a building in late 16th-century English, and derived via French and Italian ultimately from Latin ''modulus'', a measure. Models can be divided into physical models (e.g. a model plane) and abstract models (e.g. mathematical expressions describing behavioural patterns). Abstract or conceptual models are central to philosophy of science, as almost every scientific theory effectively embeds some kind of model of the physical or human sphere. In commerce, "model" can refer to a specific design of a product as displayed in a catalogue or show room (e.g. Ford Model T), and by extension to the sold product itself. Types of models include: Physical model A physical model (most commonly referred to simply as a model but in this context distinguished from a conceptual model) is a smaller or larger physical copy of an object. The object being modelled may be small (for ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Co-transport
In cellular biology, ''active transport'' is the movement of molecules or ions across a cell membrane from a region of lower concentration to a region of higher concentration—against the concentration gradient. Active transport requires cellular energy to achieve this movement. There are two types of active transport: primary active transport that uses adenosine triphosphate ( ATP), and secondary active transport that uses an electrochemical gradient. Some examples of active transport include: * Phagocytosis of bacteria by macrophages * Movement of calcium ions out of cardiac muscle cells * Transportation of amino acids across the intestinal lining in the human gut * Secretion of proteins such as enzymes, peptide hormones, and antibodies from various cells * Functioning of white blood cells to defend invading diseases Active cellular transportation (ACT) Unlike passive transport, which uses the kinetic energy and natural entropy of molecules moving down a gradient, active ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Symporter
A symporter is an integral membrane protein that is involved in the transport of two (or more) different molecules across the cell membrane in the same direction. The symporter works in the plasma membrane and molecules are transported across the cell membrane at the same time, and is, therefore, a type of cotransporter. The transporter is called a symporter, because the molecules will travel in the same direction in relation to each other. This is in contrast to the antiport transporter. Typically, the ion(s) will move down the electrochemical gradient, allowing the other molecule(s) to move against the concentration gradient. The movement of the ion(s) across the membrane is facilitated diffusion, and is coupled with the active transport of the molecule(s). In symport, two molecule move in 'similar direction' at the 'same time' Example of symport:- movement of glucose along with sodium ion Examples SGLT1 in the intestinal epithelium transports sodium ions (Na+) and glucose acro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
