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Autoreceptor
An autoreceptor is a type of receptor located in the membranes of nerve cells. It serves as part of a negative feedback loop in signal transduction. It is only sensitive to the neurotransmitters or hormones released by the neuron on which the autoreceptor sits. Similarly, a heteroreceptor is sensitive to neurotransmitters and hormones that are not released by the cell on which it sits. A given receptor can act as either an autoreceptor or a heteroreceptor, depending upon the type of transmitter released by the cell on which it is embedded. Autoreceptors may be located in any part of the cell membrane: in the dendrites, the cell body, the axon, or the axon terminals. Canonically, a presynaptic neuron releases a neurotransmitter across a synaptic cleft to be detected by the receptors on a postsynaptic neuron. Autoreceptors on the presynaptic neuron will also detect this neurotransmitter and often function to control internal cell processes, typically inhibiting further release or ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Heteroreceptor
A heteroreceptor is a receptor regulating the synthesis and/or the release of mediators other than its own ligand. Heteroreceptors respond to neurotransmitters, neuromodulators, or neurohormones released from adjacent neurons or cells; they are opposite to autoreceptors, which are sensitive only to neurotransmitters or hormones released by the cell in whose wall they are embedded. Examples * Norepinephrine can influence the release of acetylcholine from parasympathetic neurons by acting on α2 adrenergic (α2A, α2B, and α2C) heteroreceptors. * Acetylcholine can influence the release of norepinephrine from sympathetic neurons by acting on muscarinic-2 and muscarinic-4 heteroreceptors. * CB1 negatively modulates the release of GABA and glutamate, playing a crucial role in maintaining a homeostasis between excitatory and inhibitory transmission. * Glutamate released from an excitatory neuron escapes from the synaptic cleft Chemical synapses are biological junctions thro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
TAAR1
Trace amine-associated receptor 1 (TAAR1) is a trace amine-associated receptor (TAAR) protein that in humans is encoded by the ''TAAR1'' gene. TAAR1 is an intracellular amine-activated and G protein-coupled receptor (GPCR) that is primarily expressed in several peripheral organs and cells (e.g., the stomach, small intestine, duodenum, and white blood cells), astrocytes, and in the intracellular milieu within the presynaptic plasma membrane (i.e., axon terminal) of monoamine neurons in the central nervous system (CNS). TAAR1 was discovered in 2001 by two independent groups of investigators, Borowski ''et al.'' and Bunzow ''et al.'' TAAR1 is one of six functional human trace amine-associated receptors, which are so named for their ability to bind endogenous amines that occur in tissues at trace concentrations. TAAR1 plays a significant role in regulating neurotransmission in dopamine, norepinephrine, and serotonin neurons in the CNS; it also affects immune system and neuroimmun ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Axon Terminal
Axon terminals (also called synaptic boutons, terminal boutons, or end-feet) are distal terminations of the telodendria (branches) of an axon. An axon, also called a nerve fiber, is a long, slender projection of a nerve cell, or neuron, that conducts electrical impulses called action potentials away from the neuron's cell body, or soma, in order to transmit those impulses to other neurons, muscle cells or glands. Neurons are interconnected in complex arrangements, and use electrochemical signals and neurotransmitter chemicals to transmit impulses from one neuron to the next; axon terminals are separated from neighboring neurons by a small gap called a synapse, across which impulses are sent. The axon terminal, and the neuron from which it comes, is sometimes referred to as the "presynaptic" neuron. Nerve impulse release Neurotransmitters are packaged into synaptic vesicles that cluster beneath the axon terminal membrane on the presynaptic side of a synapse. The axonal terminals ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Receptor (biochemistry)
In biochemistry and pharmacology, receptors are chemical structures, composed of protein, that receive and transduce signals that may be integrated into biological systems. These signals are typically chemical messengers which bind to a receptor and cause some form of cellular/tissue response, e.g. a change in the electrical activity of a cell. There are three main ways the action of the receptor can be classified: relay of signal, amplification, or integration. Relaying sends the signal onward, amplification increases the effect of a single ligand, and integration allows the signal to be incorporated into another biochemical pathway. Receptor proteins can be classified by their location. Transmembrane receptors include ligand-gated ion channels, G protein-coupled receptors, and enzyme-linked hormone receptors. Intracellular receptors are those found inside the cell, and include cytoplasmic receptors and nuclear receptors. A molecule that binds to a receptor is called a li ... [...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 t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cyclic Nucleotide-gated Ion Channel
Cycle, cycles, or cyclic may refer to: Anthropology and social sciences * Cyclic history, a theory of history * Cyclical theory, a theory of American political history associated with Arthur Schlesinger, Sr. * Social cycle, various cycles in social sciences ** Business cycle, the downward and upward movement of gross domestic product (GDP) around its ostensible, long-term growth trend Arts, entertainment, and media Films * ''Cycle'' (2008 film), a Malayalam film * ''Cycle'' (2017 film), a Marathi film Literature * ''Cycle'' (magazine), an American motorcycling enthusiast magazine * Literary cycle, a group of stories focused on common figures Music Musical terminology * Cycle (music), a set of musical pieces that belong together **Cyclic form, a technique of construction involving multiple sections or movements **Interval cycle, a collection of pitch classes generated from a sequence of the same interval class **Song cycle, individually complete songs designed to be perfor ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Trace Amines
Trace amines are an endogenous group of TAAR1 agonist, trace amine-associated receptor 1 (TAAR1) agonists – and hence, monoaminergic neuromodulators – that are structurally and metabolically related to classical monoamine neurotransmitters. Compared to the classical monoamines, they are present in trace concentrations. They are distributed heterogeneously throughout the mammalian brain and peripheral nervous tissues and exhibit high rates of metabolism. Although they can be synthesized within parent monoamine neurotransmitter systems, there is evidence that suggests that some of them may comprise their own independent neurotransmitter systems. Trace amines play significant roles in regulating the quantity of monoamine neurotransmitters in the synaptic cleft of monoamine neurons with . They have well-characterized presynaptic ''amphetamine-like'' effects on these monoamine neurons via TAAR1 activation; specifically, by activating TAAR1 in neurons they promote the release and p ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Translation (biology)
In molecular biology and genetics, translation is the process in which ribosomes in the cytoplasm or endoplasmic reticulum synthesize proteins after the process of transcription of DNA to RNA in the cell's nucleus. The entire process is called gene expression. In translation, messenger RNA (mRNA) is decoded in a ribosome, outside the nucleus, to produce a specific amino acid chain, or polypeptide. The polypeptide later folds into an active protein and performs its functions in the cell. The ribosome facilitates decoding by inducing the binding of complementary tRNA anticodon sequences to mRNA codons. The tRNAs carry specific amino acids that are chained together into a polypeptide as the mRNA passes through and is "read" by the ribosome. Translation proceeds in three phases: # Initiation: The ribosome assembles around the target mRNA. The first tRNA is attached at the start codon. # Elongation: The last tRNA validated by the small ribosomal subunit (''accom ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Adenylyl Cyclase
Adenylate cyclase (EC 4.6.1.1, also commonly known as adenyl cyclase and adenylyl cyclase, abbreviated AC) is an enzyme with systematic name ATP diphosphate-lyase (cyclizing; 3′,5′-cyclic-AMP-forming). It catalyzes the following reaction: :ATP = 3′,5′-cyclic AMP + diphosphate It has key regulatory roles in essentially all cells. It is the most polyphyletic known enzyme: six distinct classes have been described, all catalyzing the same reaction but representing unrelated gene families with no known sequence or structural homology. The best known class of adenylyl cyclases is class III or AC-III (Roman numerals are used for classes). AC-III occurs widely in eukaryotes and has important roles in many human tissues. All classes of adenylyl cyclase catalyse the conversion of adenosine triphosphate (ATP) to 3',5'-cyclic AMP (cAMP) and pyrophosphate.Magnesium ions are generally required and appear to be closely involved in the enzymatic mechanism. The cAMP produced by A ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Monoaminergic
Monoaminergic means "working on monoamine neurotransmitters", which include serotonin, dopamine, norepinephrine, epinephrine, and histamine. A monoaminergic, or monoaminergic drug, is a chemical, which functions to directly modulate the serotonin, dopamine, norepinephrine, epinephrine, and/or histamine neurotransmitter systems in the brain. Monoaminergics include catecholaminergics (which can be further divided into adrenergics and dopaminergics), serotonergics, and histaminergics. Examples of monoaminergic drugs include monoamine precursors, monoamine receptor modulators, monoamine reuptake inhibitors, monoamine releasing agents, and monoamine metabolism modulators such as monoamine oxidase inhibitors. See also * Adenosinergic * Adrenergic * Cannabinoidergic * Cholinergic * Dopaminergic * GABAergic * Glycinergic * Histaminergic * Melatonergic * Opioidergic * Serotonergic Serotonergic () or serotoninergic () means "pertaining to or affecting serotonin". S ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 genetic ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
D2sh
Dopamine receptor D2, also known as D2R, is a protein that, in humans, is encoded by the ''DRD2'' gene. After work from Paul Greengard's lab had suggested that dopamine receptors were the site of action of antipsychotic drugs, several groups, including those of Solomon Snyder and Philip Seeman used a radiolabeled antipsychotic drug to identify what is now known as the dopamine D2 receptor. The dopamine D2 receptor is the main receptor for most antipsychotic drugs. The structure of DRD2 in complex with the atypical antipsychotic risperidone has been determined. Function D2 receptors are coupled to Gi subtype of G protein. This G protein-coupled receptor inhibits adenylyl cyclase activity. In mice, regulation of D2R surface expression by the neuronal calcium sensor-1 (NCS-1) in the dentate gyrus is involved in exploration, synaptic plasticity and memory formation. Studies have shown potential roles for D2R in retrieval of fear memories in the prelimbic cortex and in discr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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