A neurotransmitter is a signaling molecule secreted by a neuron to affect another cell across a synapse. The cell receiving the signal, or target cell, may be another neuron, but could also be a gland or muscle cell.
5-HT receptors, 5-hydroxytryptamine receptors, or serotonin receptors, are a group of G protein-coupled receptor and ligand-gated ion channels found in the central and peripheral nervous systems. They mediate both excitatory and inhibitory neurotransmission. The serotonin receptors are activated by the neurotransmitter serotonin, which acts as their natural ligand.
Neuropsychopharmacology, an interdisciplinary science related to psychopharmacology and fundamental neuroscience, is the study of the neural mechanisms that drugs act upon to influence behavior. It entails research of mechanisms of neuropathology, pharmacodynamics, psychiatric illness, and states of consciousness. These studies are instigated at the detailed level involving neurotransmission/receptor activity, bio-chemical processes, and neural circuitry. Neuropsychopharmacology supersedes psychopharmacology in the areas of "how" and "why", and additionally addresses other issues of brain function. Accordingly, the clinical aspect of the field includes psychiatric (psychoactive) as well as neurologic (non-psychoactive) pharmacology-based treatments. Developments in neuropsychopharmacology may directly impact the studies of anxiety disorders, affective disorders, psychotic disorders, degenerative disorders, eating behavior, and sleep behavior.
Desmetramadol (INN), also known as O-desmethyltramadol (O-DSMT), is an opioid analgesic and the main active metabolite of tramadol. Tramadol is demethylated by the liver enzyme CYP2D6 in the same way as codeine, and so similarly to the variation in effects seen with codeine, individuals who have a less active form of CYP2D6 will tend to get reduced analgesic effects from tramadol. This also results in a ceiling effect which limits tramadol's range of therapeutic benefits to the treatment of moderate pain.
SB-277,011A is a drug which acts as a potent and selective dopamine D3 receptor antagonist, which is around 80-100x selective for D3 over D2, and lacks any partial agonist activity.
The serotonin 1A receptor is a subtype of serotonin receptors, or 5-HT receptors, that binds serotonin, also known as 5-HT, a neurotransmitter. 5-HT1A is expressed in the brain, spleen, and neonatal kidney. It is a G protein-coupled receptor (GPCR), coupled to the Gi protein, and its activation in the brain mediates hyperpolarisation and reduction of firing rate of the postsynaptic neuron. In humans, the serotonin 1A receptor is encoded by the HTR1A gene.
5-hydroxytryptamine receptor 1B also known as the 5-HT1B receptor is a protein that in humans is encoded by the HTR1B gene. The 5-HT1B receptor is a 5-HT receptor subtype.
The 5HT6 receptor is a subtype of 5HT receptor that binds the endogenous neurotransmitter serotonin (5-hydroxytryptamine, 5HT). It is a G protein-coupled receptor (GPCR) that is coupled to Gs and mediates excitatory neurotransmission. HTR6 denotes the human gene encoding for the receptor.
LY-341495 is a research drug developed by the pharmaceutical company Eli Lilly, which acts as a potent and selective orthosteric antagonist for the group II metabotropic glutamate receptors (mGluR2/3).
SB-271046 is a drug which is used in scientific research. It was one of the first selective 5-HT6 receptor antagonists to be discovered, and was found through high-throughput screening of the SmithKline Beecham Compound Bank using cloned 5-HT6 receptors as a target, with an initial lead compound being developed into SB-271046 through a structure-activity relationship (SAR) study. SB-271046 was found to be potent and selective in vitro and had good oral bioavailability in vivo, but had poor penetration across the blood–brain barrier, so further SAR work was then conducted, which led to improved 5-HT6 antagonists such as SB-357,134 and SB-399,885.
RS-102221 is a drug developed by Hoffmann–La Roche, which was one of the first compounds discovered that acts as a potent and selective antagonist at the serotonin 5-HT2C receptor, with around 100x selectivity over the closely related 5-HT2A and 5-HT2B receptors. It has anxiolytic effects in animal studies, increases the effectiveness of SSRI antidepressants, and shows a complex interaction with cocaine, increasing some effects but decreasing others, reflecting a role for the 5-HT2C receptor in regulation of the dopamine signalling system in the brain.
SB-216641 is a drug which is a selective antagonist for the serotonin receptor 5-HT1B, with around 25x selectivity over the closely related 5-HT1D receptor. It is used in scientific research, and has demonstrated anxiolytic effects in animal studies.
SB-269970 is a drug and research chemical developed by GlaxoSmithKline used in scientific studies. It is believed to act as a selective 5-HT7 receptor antagonist (EC50 = 1.25 nM) (or possibly inverse agonist). A subsequent study in guinea pig at a concentration of 10 μM showed that it also blocks the α2-adrenergic receptor. The large difference in test concentrations however confirms the selectivity of SB-269970 for the 5-HT7 receptor.
SB-334867 is an orexin antagonist. It was the first non-peptide antagonist developed that is selective for the orexin receptor subtype OX1, with around 50x selectivity for OX1 over OX2 receptors. It has been shown to produce sedative and anorectic effects in animals, and has been useful in characterising the orexinergic regulation of brain systems involved with appetite and sleep, as well as other physiological processes. The hydrochloride salt of SB-334867 has been demonstrated to be hydrolytically unstable, both in solution and as the solid. Orexin antagonists have multiple potential clinical applications including the treatment of drug addiction, insomnia, obesity and diabetes.
SB-649,915 is a serotonin reuptake inhibitor and 5-HT1A and 5-HT1B receptor antagonist which is being investigated for its antidepressant effects. Relative to the selective serotonin reuptake inhibitors (SSRIs), SB-649,915 has a faster onset of action and may also have greater clinical efficacy as well. This can be attributed to blockade of 5-HT1A and 5-HT1B autoreceptors which inhibit serotonin release.
SB-215505 is a drug which acts as a potent and selective antagonist at the serotonin 5-HT2B receptor, with good selectivity over the related 5-HT2A and 5-HT2C receptors. It is used in scientific research into the function of the 5-HT2 family of receptors, especially to study the role of 5-HT2B receptors in the heart, and to distinguish 5-HT2B-mediated responses from those produced by 5-HT2A or 5-HT2C.
WAY-181187 is a high affinity and selective 5-HT6 receptor full agonist. It induces robust increases in extracellular GABA levels in the frontal cortex, hippocampus, striatum, and amygdala of rats without affecting concentrations in the nucleus accumbens or thalamus, and has modest to no effects on norepinephrine, serotonin, dopamine, or glutamate levels in these areas. WAY-181187 has demonstrated preclinical efficacy in rodent models of depression, anxiety, and notably obsessive-compulsive disorder, though it has also been shown to impair cognition and memory.
SB-206553 is a drug which acts as a mixed antagonist for the 5-HT2B and 5-HT2C serotonin receptors. It has anxiolytic properties in animal studies and interacts with a range of other drugs. It has also been shown to act as a positive allosteric modulator of α7 nicotinic acetylcholine receptors. Modified derivatives of SB-206553 have been used to probe the structure of the 5-HT2B receptor.
SB-243213 is a research chemical which acts as a selective inverse agonist for the 5HT2C receptor and has anxiolytic effects. It has better than 100x selectivity for 5-HT2C over all other receptor subtypes tested, and a longer duration of action compared to older 5-HT2C antagonist ligands.
