The N-methyl-D-aspartatereceptor (also known as the NMDA receptor or NMDAR), is a glutamate receptor and predominantly Ca2+ ion channel found in neurons. The NMDA receptor is one of three types of ionotropic glutamate receptors, the other two being AMPA and kainate receptors. Depending on its subunit composition, its ligands are glutamate and glycine (or D-serine). However, the binding of the ligands is typically not sufficient to open the channel as it may be blocked by Mg2+ ions which are only removed when the neuron is sufficiently depolarized. Thus, the channel acts as a "coincidence detector" and only once both of these conditions are met, the channel opens and it allows positively charged ions (cations) to flow through the cell membrane. The NMDA receptor is thought to be very important for controlling synaptic plasticity and mediating learning and memory functions.
Nootropics, colloquially brain supplements, smart drugs and cognitive enhancers, are natural, semisynthetic or synthetic compounds which purportedly improve cognitive functions, such as executive functions, attention or memory.
Piracetam is a drug that has efficacy in cognitive disorders, vertigo, cortical myoclonus, dyslexia, and sickle cell anemia; sources differ on its usefulness for dementia. Piracetam is sold as a medication in many European countries. Sale of piracetam is not illegal in the United States, although it is not regulated nor approved by the FDA, so it is legally sold for research use only.
Donepezil, sold under the brand name Aricept among others, is a medication used to treat dementia of the Alzheimer's type. It appears to result in a small benefit in mental function and ability to function. Use, however, has not been shown to change the progression of the disease. Treatment should be stopped if no benefit is seen. It is taken by mouth or via a transdermal patch.
Ampakines or AMPAkines are a subgroup of AMPA receptor positive allosteric modulators with a benzamide or closely related chemical structure. They are also known as "CX compounds". Ampakines take their name from the AMPA receptor (AMPAR), a type of ionotropic glutamate receptor with which the ampakines interact and act as positive allosteric modulators (PAMs) of. Although all ampakines are AMPAR PAMs, not all AMPAR PAMs are ampakines.
CX717 is an ampakine compound created by Christopher Marrs and Gary Rogers in 1996 at Cortex Pharmaceuticals. It affects the neurotransmitter glutamate, with trials showing the drug improves cognitive functioning and memory.
Racetams, also sometimes known simply as pyrrolidones, are a class of drugs that share a pyrrolidone nucleus. Many, but not all, specifically have a 2-oxo-1-pyrrolidine acetamide (piracetam) nucleus. Some racetams, such as piracetam, aniracetam, oxiracetam, pramiracetam, and phenylpiracetam, are considered nootropics. Phenylpiracetam is also a stimulant. Others, such as levetiracetam, brivaracetam, and seletracetam, are anticonvulsants.
Phenylpiracetam, also known as fonturacetam and sold under the brand names Phenotropil, Actitropil, and Carphedon among others, is a stimulant and nootropic medication used in Russia and certain other Eastern European countries in the treatment of cerebrovascular deficiency, depression, apathy, and attention, and memory problems, among other indications. It is also used in Russian cosmonauts to improve physical, mental, and cognitive abilities. The drug is taken by mouth.
Dopaminergic means "related to dopamine", a common neurotransmitter. Dopaminergic substances or actions increase dopamine-related activity in the brain.
Neuromodulation is the physiological process by which a given neuron uses one or more chemicals to regulate diverse populations of neurons. Neuromodulators typically bind to metabotropic, G-protein coupled receptors (GPCRs) to initiate a second messenger signaling cascade that induces a broad, long-lasting signal. This modulation can last for hundreds of milliseconds to several minutes. Some of the effects of neuromodulators include altering intrinsic firing activity, increasing or decreasing voltage-dependent currents, altering synaptic efficacy, increasing bursting activity and reconfiguring synaptic connectivity.
Trace amines are an endogenous group of 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.
Ispronicline is an experimental drug which acts as a partial agonist at neural nicotinic acetylcholine receptors. It progressed to phase II clinical trials for the treatment of dementia and Alzheimer's disease, but is no longer under development.
N-Phenylacetyl-l-prolylglycine ethyl ester is promoted as a nootropic and is a prodrug of cyclic glycine-proline. Other names include the brand name Noopept, developmental code GVS-111, and proposed INN omberacetam.
Brexpiprazole, sold under the brand name Rexulti among others, is an atypical antipsychotic medication used for the treatment of major depressive disorder, schizophrenia, and agitation associated with dementia due to Alzheimer's disease.
ALTO-100, previously known as NSI-189, is a drug described as a hippocampal neurogenesis stimulant and indirect brain-derived neurotrophic factor (BDNF) modulator which is under development for the treatment of major depressive disorder (MDD), bipolar depression, and post-traumatic stress disorder (PTSD). There has also been interest in ALTO-100 for possible treatment of cognitive impairment and neurodegeneration. It is taken by mouth.
Blarcamesine is an experimental drug which is under development for the treatment of Alzheimer's disease and a variety of other indications.
AMPA receptor positive allosteric modulators are positive allosteric modulators (PAMs) of the AMPA receptor (AMPR), a type of ionotropic glutamate receptor which mediates most fast synaptic neurotransmission in the central nervous system.
Phenserine is a synthetic drug which has been investigated as a medication to treat Alzheimer's disease (AD), as the drug exhibits neuroprotective and neurotrophic effects.
Xanomeline/trospium chloride, sold under the brand name Cobenfy, is a fixed-dose combination medication used for the treatment of schizophrenia. It contains xanomeline, a muscarinic agonist; and trospium chloride, a muscarinic antagonist. Xanomeline is a functionally preferring muscarinic M4 and M1 receptor agonist. Trospium chloride is a non-selective muscarinic antagonist.
Glovadalen (developmental code name UCB-0022) is a dopamine D1 receptor positive allosteric modulator which is under development for the treatment of Parkinson's disease. It has been found to potentiate the capacity of dopamine to activate the D1 receptor by 10-fold in vitro with no actions on other dopamine receptors. As of May 2024, glovadalen is in phase 2 clinical trials for this indication. The drug is under development by UCB Biopharma. It is described as an orally active, centrally penetrant small molecule.
