Amphetamine is a strong central nervous system (CNS) stimulant that is used in the treatment of attention deficit hyperactivity disorder (ADHD), narcolepsy, and obesity. Amphetamine was discovered in 1887 and exists as two enantiomers: levoamphetamine and dextroamphetamine. Amphetamine properly refers to a specific chemical, the racemic free base, which is equal parts of the two enantiomers in their pure amine forms. The term is frequently used informally to refer to any combination of the enantiomers, or to either of them alone. Historically, it has been used to treat nasal congestion and depression. Amphetamine is also used as an athletic performance enhancer and cognitive enhancer, and recreationally as an aphrodisiac and euphoriant. It is a prescription drug in many countries, and unauthorized possession and distribution of amphetamine are often tightly controlled due to the significant health risks associated with recreational use.
Phencyclidine or phenylcyclohexyl piperidine (PCP), also known as angel dust among other names, is a dissociative hallucinogenic drug used for its mind-altering effects. PCP may cause hallucinations, distorted perceptions of sounds, and violent behavior. As a recreational drug, it is typically smoked, but may be taken by mouth, snorted, or injected. It may also be mixed with cannabis or tobacco.
Chlorpromazine (CPZ), marketed under the brand names Thorazine and Largactil among others, is an antipsychotic medication. It is primarily used to treat psychotic disorders such as schizophrenia. Other uses include the treatment of bipolar disorder, severe behavioral problems in children including those with attention deficit hyperactivity disorder, nausea and vomiting, anxiety before surgery, and hiccups that do not improve following other measures. It can be given by mouth, by injection into a muscle, or into a vein.
Aripiprazole, sold under the brand names Abilify and Aristada among others, is an atypical antipsychotic. It is primarily used in the treatment of schizophrenia and bipolar disorder. Other uses include as an add-on treatment in major depressive disorder, tic disorders and irritability associated with autism. It is taken by mouth or injection into a muscle. A Cochrane review found low-quality evidence of effectiveness in treating schizophrenia.
Mirtazapine, sold under the brand name Remeron among others, is an atypical antidepressant, and as such is used primarily to treat depression. Its effects may take up to four weeks, but can also manifest as early as one to two weeks. It is often used in cases of depression complicated by anxiety or insomnia. The effectiveness of Mirtazapine is comparable to other commonly prescribed antidepressants. It is taken by mouth.
Dizocilpine (INN), also known as MK-801, is an uncompetitive antagonist of the N-Methyl-D-aspartate (NMDA) receptor, a glutamate receptor, discovered by a team at Merck in 1982. Glutamate is the brain's primary excitatory neurotransmitter. The channel is normally blocked with a magnesium ion and requires depolarization of the neuron to remove the magnesium and allow the glutamate to open the channel, causing an influx of calcium, which then leads to subsequent depolarization. Dizocilpine binds inside the ion channel of the receptor at several of PCP's binding sites thus preventing the flow of ions, including calcium (Ca2+), through the channel. Dizocilpine blocks NMDA receptors in a use- and voltage-dependent manner, since the channel must open for the drug to bind inside it. The drug acts as a potent anti-convulsant and probably has dissociative anesthetic properties, but it is not used clinically for this purpose because of the discovery of brain lesions, called Olney's lesions (see below), in laboratory rats. Dizocilpine is also associated with a number of negative side effects, including cognitive disruption and psychotic-spectrum reactions. It inhibits the induction of long term potentiation and has been found to impair the acquisition of difficult, but not easy, learning tasks in rats and primates. Because of these effects of dizocilpine, the NMDA receptor pore-blocker ketamine is used instead as a dissociative anesthetic in human medical procedures. While ketamine may also trigger temporary psychosis in certain individuals, its short half-life and lower potency make it a much safer clinical option. However, dizocilpine is the most frequently used uncompetitive NMDA receptor antagonist in animal models to mimic psychosis for experimental purposes.
Pindolol, sold under the brand name Visken among others, is a nonselective beta blocker which is used in the treatment of hypertension. It is also an antagonist of the serotonin 5-HT1A receptor, preferentially blocking inhibitory 5-HT1A autoreceptors, and has been researched as an add-on therapy to selective serotonin reuptake inhibitors (SSRIs) in the treatment of depression.
BIMU-8 is a drug which acts as a 5-HT4 receptor selective agonist. BIMU-8 was one of the first compounds of this class. The main action of BIMU-8 is to increase the rate of respiration by activating an area of the brain stem known as the pre-Botzinger complex.
Fencamfamin (INN), also known as fencamfamine or by the brand names Glucoenergan and Reactivan, is a stimulant which was developed by Merck in the 1960s.
The serotonin 1A receptor is a subtype of serotonin receptor, or 5-HT receptor, 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.
RB-101 is a drug that acts as an enkephalinase inhibitor, which is used in scientific research.
SB-242084 is a psychoactive drug and research chemical which acts as a selective antagonist for the 5HT2C receptor. It has anxiolytic effects, and enhances dopamine signalling in the limbic system, as well as having complex effects on the dopamine release produced by cocaine, increasing it in some brain regions but reducing it in others. It has been shown to increase the effectiveness of the selective serotonin reuptake inhibitor (SSRI) class of antidepressants, and may also reduce their side effects. In animal studies, SB-242084 produced stimulant-type activity and reinforcing effects, somewhat similar to but much weaker than cocaine or amphetamines.
Blonanserin, sold under the brand name Lonasen, is a relatively new atypical antipsychotic commercialized by Dainippon Sumitomo Pharma in Japan and Korea for the treatment of schizophrenia. Relative to many other antipsychotics, blonanserin has an improved tolerability profile, lacking side effects such as extrapyramidal symptoms, excessive sedation, or hypotension. As with many second-generation (atypical) antipsychotics it is significantly more efficacious in the treatment of the negative symptoms of schizophrenia compared to first-generation (typical) antipsychotics such as haloperidol.
Conditioned place preference (CPP) is a form of Pavlovian conditioning used to measure the motivational effects of objects or experiences. By measuring the amount of time an animal spends in an area that has been associated with a stimulus, researchers can infer the animal's liking for the stimulus. This paradigm can also be used to measure conditioned place aversion with an identical procedure involving aversive stimuli instead. Both procedures usually involve mice or rats as subjects. This procedure can be used to measure extinction and reinstatement of the conditioned stimulus. Certain drugs are used in this paradigm to measure their reinforcing properties. Two different methods are used to choose the compartments to be conditioned, and these are biased vs. unbiased. The biased method allows the animal to explore the apparatus, and the compartment they least prefer is the one that the drug is administered in and the one they most prefer is the one where the vehicle is injected. This method allows the animal to choose the compartment they get the drug and vehicle in. In comparison, the unbiased method does not allow the animal to choose what compartment they get the drug and vehicle in and instead the researcher chooses the compartments.
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.
Pimavanserin , sold under the brand name Nuplazid, is an atypical antipsychotic which is approved for the treatment of Parkinson's disease psychosis and is also being studied for the treatment of Alzheimer’s disease psychosis, schizophrenia, agitation, and major depressive disorder. Unlike other antipsychotics, pimavanserin is not a dopamine receptor antagonist.
PNU-99,194(A) (or U-99,194(A)) is a drug which acts as a moderately selective D3 receptor antagonist with ~15-30-fold preference for D3 over the D2 subtype. Though it has substantially greater preference for D3 over D2, the latter receptor does still play some role in its effects, as evidenced by the fact that PNU-99,194 weakly stimulates both prolactin secretion and striatal dopamine synthesis, actions it does not share with the more selective (100-fold) D3 receptor antagonists S-14,297 and GR-103,691.
Cariprazine, sold under the brand names Vraylar in the United States and Reagila in the European Union, is an atypical antipsychotic which is used in the treatment of schizophrenia, bipolar mania, and bipolar depression. It acts primarily as a D3 receptor and D2 receptor partial agonist, with high selectivity for the D3 receptor. Positive Phase III study results were published for schizophrenia and mania in early 2012, and for bipolar disorder I depression from a Phase II trial in 2015. It is also potentially useful as an add-on therapy in major depressive disorder.
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.
F-15,063 is an orally active potential antipsychotic, and an antagonist at the D2/D3 receptors, partial agonist at the D4 receptor, and agonist at the 5-HT1A receptors. It has greater efficacy at the 5-HT1A receptors than other antipsychotics, such as clozapine, aripiprazole, and ziprasidone. This greater efficacy may lead to enhanced antipsychotic properties, as antipsychotics that lack 5-HT1A affinity are associated with increased risk of extrapyramidal symptoms, and lack of activity against the negative symptoms of schizophrenia.
