1.
Drug
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A drug is any substance that, when inhaled, injected, smoked, consumed, absorbed via a patch on the skin, or dissolved under the tongue, causes a physiological change in the body. In pharmacology, a drug, also called a medication or medicine, is a chemical substance used to treat, cure, prevent. Traditionally drugs were obtained through extraction from plants, but more recently also by organic synthesis. Pharmaceutical drugs may be used for a duration, or on a regular basis for chronic disorders. Another major classification system is the Biopharmaceutics Classification System and this classifies drugs according to their solubility and permeability or absorption properties. Psychoactive drugs are chemical substances that affect the function of the nervous system, altering perception. They include alcohol, a depressant, and the nicotine and caffeine. These three are the most widely consumed psychoactive drugs worldwide and are also considered recreational drugs since they are used for rather than medicinal purposes. Other recreational drugs include hallucinogens, opiates and amphetamines and some of these are used in spiritual or religious settings. Some drugs can cause addiction and all drugs can have side effects, excessive use of stimulants can promote stimulant psychosis. Many recreational drugs are illicit and international such as the Single Convention on Narcotic Drugs exist for the purpose of their prohibition. The transitive verb to drug arose later and invokes the psychoactive rather than properties of a substance. A medication or medicine is a drug taken to cure or ameliorate any symptoms of an illness or medical condition, the use may also be as preventive medicine that has future benefits but does not treat any existing or pre-existing diseases or symptoms. In the United Kingdom, behind-the-counter medicines are called pharmacy medicines which can only be sold in registered pharmacies and these medications are designated by the letter P on the label. The range of medicines available without a prescription varies from country to country, medications are typically produced by pharmaceutical companies and are often patented to give the developer exclusive rights to produce them. Those that are not patented are called generic drugs since they can be produced by other companies without restrictions or licenses from the patent holder, pharmaceutical drugs are usually categorised into drug classes. A group of drugs will share a chemical structure, or have the same mechanism of action. Another major classification system is the Biopharmaceutics Classification System and this groups drugs according to their solubility and permeability or absorption properties
2.
Dopamine
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Dopamine is an organic chemical of the catecholamine and phenethylamine families that plays several important roles in the brain and body. It is an amine synthesized by removing a carboxyl group from a molecule of its precursor chemical L-DOPA, dopamine is also synthesized in plants and most multicellular animals. In the brain, dopamine functions as a neurotransmitter—a chemical released by neurons to send signals to nerve cells. The brain includes several distinct dopamine pathways, one of plays a major role in reward-motivated behavior. Most types of rewards increase the level of dopamine in the brain, other brain dopamine pathways are involved in motor control and in controlling the release of various hormones. These pathways and cell groups form a system which is neuromodulatory. Outside the central system, dopamine functions primarily as a local chemical messenger. With the exception of the vessels, dopamine in each of these peripheral systems is synthesized locally. Several important diseases of the system are associated with dysfunctions of the dopamine system. Parkinsons disease, a condition causing tremor and motor impairment, is caused by a loss of dopamine-secreting neurons in an area of the midbrain called the substantia nigra. Its metabolic precursor L-DOPA can be manufactured, and in its pure form marketed as Levodopa is the most widely used treatment for the condition. There is evidence that schizophrenia involves altered levels of dopamine activity, similar dopamine antagonist drugs are also some of the most effective anti-nausea agents. Restless legs syndrome and attention deficit hyperactivity disorder are associated with decreased dopamine activity, dopaminergic stimulants can be addictive in high doses, but some are used at lower doses to treat ADHD. A dopamine molecule consists of a structure with one amine group attached via an ethyl chain. As such, dopamine is the simplest possible catecholamine, a family that includes the neurotransmitters norepinephrine and epinephrine. The presence of a ring with this amine attachment makes it a substituted phenethylamine. Like most amines, dopamine is an organic base, as a base, it is generally protonated in acidic environments. The protonated form is highly water-soluble and relatively stable, but can become oxidized if exposed to oxygen or other oxidants, in basic environments, dopamine is not protonated
3.
Jmol
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Jmol is computer software for molecular modelling chemical structures in 3-dimensions. Jmol returns a 3D representation of a molecule that may be used as a teaching tool and it is written in the programming language Java, so it can run on the operating systems Windows, macOS, Linux, and Unix, if Java is installed. It is free and open-source software released under a GNU Lesser General Public License version 2.0, a standalone application and a software development kit exist that can be integrated into other Java applications, such as Bioclipse and Taverna. A popular feature is an applet that can be integrated into web pages to display molecules in a variety of ways, for example, molecules can be displayed as ball-and-stick models, space-filling models, ribbon diagrams, etc. Jmol supports a range of chemical file formats, including Protein Data Bank, Crystallographic Information File, MDL Molfile. There is also a JavaScript-only version, JSmol, that can be used on computers with no Java, the Jmol applet, among other abilities, offers an alternative to the Chime plug-in, which is no longer under active development. While Jmol has many features that Chime lacks, it does not claim to reproduce all Chime functions, most notably, Chime requires plug-in installation and Internet Explorer 6.0 or Firefox 2.0 on Microsoft Windows, or Netscape Communicator 4.8 on Mac OS9. Jmol requires Java installation and operates on a variety of platforms. For example, Jmol is fully functional in Mozilla Firefox, Internet Explorer, Opera, Google Chrome, fast and Scriptable Molecular Graphics in Web Browsers without Java3D
4.
European Chemicals Agency
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ECHA is the driving force among regulatory authorities in implementing the EUs chemicals legislation. ECHA helps companies to comply with the legislation, advances the safe use of chemicals, provides information on chemicals and it is located in Helsinki, Finland. The Agency, headed by Executive Director Geert Dancet, started working on 1 June 2007, the REACH Regulation requires companies to provide information on the hazards, risks and safe use of chemical substances that they manufacture or import. Companies register this information with ECHA and it is freely available on their website. So far, thousands of the most hazardous and the most commonly used substances have been registered, the information is technical but gives detail on the impact of each chemical on people and the environment. This also gives European consumers the right to ask whether the goods they buy contain dangerous substances. The Classification, Labelling and Packaging Regulation introduces a globally harmonised system for classifying and labelling chemicals into the EU. This worldwide system makes it easier for workers and consumers to know the effects of chemicals, companies need to notify ECHA of the classification and labelling of their chemicals. So far, ECHA has received over 5 million notifications for more than 100000 substances, the information is freely available on their website. Consumers can check chemicals in the products they use, Biocidal products include, for example, insect repellents and disinfectants used in hospitals. The Biocidal Products Regulation ensures that there is information about these products so that consumers can use them safely. ECHA is responsible for implementing the regulation, the law on Prior Informed Consent sets guidelines for the export and import of hazardous chemicals. Through this mechanism, countries due to hazardous chemicals are informed in advance and have the possibility of rejecting their import. Substances that may have effects on human health and the environment are identified as Substances of Very High Concern 1. These are mainly substances which cause cancer, mutation or are toxic to reproduction as well as substances which persist in the body or the environment, other substances considered as SVHCs include, for example, endocrine disrupting chemicals. Companies manufacturing or importing articles containing these substances in a concentration above 0 and they are required to inform users about the presence of the substance and therefore how to use it safely. Consumers have the right to ask the retailer whether these substances are present in the products they buy, once a substance has been officially identified in the EU as being of very high concern, it will be added to a list. This list is available on ECHA’s website and shows consumers and industry which chemicals are identified as SVHCs, Substances placed on the Candidate List can then move to another list
5.
Substituted amphetamine
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The compounds in this class span a variety of pharmacological subclasses, including stimulants, empathogens, and hallucinogens, among others. Some of amphetamines substituted derivatives occur in nature, for example in the leaves of Ephedra and these have been used since antiquity for their pharmacological effects. Amphetamine was first produced at the end of the 19th century, by the 1930s, amphetamine and some of its derivative compounds found use as decongestants in the symptomatic treatment of colds and also occasionally as psychoactive agents. Their effects on the nervous system are diverse, but can be summarized by three overlapping types of activity, psychoanaleptic, hallucinogenic and empathogenic. Various substituted amphetamines may cause these actions either separately or in combination, amphetamines are a subgroup of the substituted phenethylamine class of compounds. Substitution of hydrogen results in a large class of compounds. Natives of Yemen and Ethiopia have a tradition of chewing khat leaves to achieve a stimulating effect. The active substances of khat are cathinone and, to a lesser extent, amphetamine was first synthesized in 1887 by Romanian chemist Lazăr Edeleanu, although its pharmacological effects remained unknown until the 1930s. MDMA was produced in 1912 as an intermediate product, however, this synthesis also went largely unnoticed. In the 1920s, both methamphetamine and the dextrorotatory optical isomer of amphetamine, dextroamphetamine, were synthesized and this synthesis was a by-product of a search for ephedrine, a bronchodilator used to treat asthma extracted exclusively from natural sources. Over-the-counter use of substituted amphetamines was initiated in the early 1930s by the pharmaceutical company Smith, Kline & French, as a medicine for colds and nasal congestion. Subsequently, amphetamine was used in the treatment of narcolepsy, obesity, hay fever, orthostatic hypotension, epilepsy, Parkinsons disease, alcoholism, the reinforcing effects of substituted amphetamines were quickly discovered, and the misuse of substituted amphetamines had been noted as far back as 1936. During World War II, amphetamines were used by the German military to keep their tank crews awake for long periods and it was noticed that extended rest was required after such artificially induced activity. The widespread use of substituted amphetamines began in postwar Japan and quickly spread to other countries, modified designer amphetamines gained popularity since the 1960s, such as MDA and PMA. In 1970, the United States adopted the Controlled Substances Act that limited non-medical use of substituted amphetamines, street use of PMA was noted in 1972. MDMA emerged as a substitute to MDA in the early 1970s, american chemist Alexander Shulgin first synthesized the drug in 1976 and through him the drug was briefly introduced into psychotherapy. Recreational use grew and in 1985 MDMA was banned by the US authorities in an emergency scheduling initiated by the Drug Enforcement Administration, since the mid-1990s, MDMA has become a popular entactogenic drug among the youth and quite often non-MDMA substances were sold as ecstasy. Ongoing trials are investigating its efficacy as an adjunct to psychotherapy in the management of treatment-resistant post-traumatic stress disorder
6.
Chemical synapse
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Chemical synapses are biological junctions through which neurons signals can be exchanged to each other and to non-neuronal cells such as those in muscles or glands. Chemical synapses allow neurons to form circuits within the nervous system. They are crucial to the computations that underlie perception and thought. They allow the system to connect to and control other systems of the body. At a chemical synapse, one neuron releases neurotransmitter molecules into a space that is adjacent to another neuron. The neurotransmitters are kept within small sacs called vesicles, and are released into the synaptic cleft by exocytosis and these molecules then bind to receptors on the postsynaptic cells side of the synaptic cleft. The adult human brain is estimated to contain from 1014 to 5 ×1014 synapses, every cubic millimeter of cerebral cortex contains roughly a billion of them. The word synapse comes from synaptein, which Sir Charles Scott Sherrington and colleagues coined from the Greek syn-, chemical synapses are not the only type of biological synapse, electrical and immunological synapses also exist. Without a qualifier, however, synapse commonly means chemical synapse, synapses are functional connections between neurons, or between neurons and other types of cells. A typical neuron gives rise to several thousand synapses, although there are types that make far fewer. Most synapses connect axons to dendrites, but there are other types of connections, including axon-to-cell-body, axon-to-axon. Chemical synapses pass information directionally from a cell to a postsynaptic cell and are therefore asymmetric in structure. Synaptic vesicles are docked at the plasma membrane at regions called active zones. Immediately opposite is a region of the cell containing neurotransmitter receptors. Immediately behind the postsynaptic membrane is a complex of interlinked proteins called the postsynaptic density. Proteins in the PSD are involved in anchoring and trafficking neurotransmitter receptors, the receptors and PSDs are often found in specialized protrusions from the main dendritic shaft called dendritic spines. Synapses may be described as symmetric or asymmetric, when examined under an electron microscope, asymmetric synapses are characterized by rounded vesicles in the presynaptic cell, and a prominent postsynaptic density. Symmetric synapses in contrast have flattened or elongated vesicles, and do not contain a prominent postsynaptic density, the synaptic cleft is a gap between the pre- and postsynaptic cells that is about 20 nm wide
