Amphetamines dopamine resembling

The various stimulants have no obvious chemical relationships and do not share primary neurochemical effects, despite their similar behavioral effects. Cocaines chemical strucmre does not resemble that of caffeine, nicotine, or amphetamine. Cocaine binds to the dopamine reuptake transporter in the central nervous system, effectively inhibiting dopamine reuptake. It has similar effects on the transporters that mediate norepinephrine and serotonin reuptake. As discussed later in this chapter in the section on neurochemical actions mediating stimulant reward, dopamine is very important in the reward system of the brain the increase of dopamine associated with use of cocaine probably accounts for the high dependence potential of the drug. 

The phenylalkylamine hallucinogens show a close structural resemblance to the catecholamines, noradrenahne and dopamine. The prototype structure is found in mescaline, a naturally occurring substance. Modification of the mescaline molecule has led to synthetic amphetamine derivatives with hallucinogenic action. 

Investigation of the neurochemical substrates for the psychostimulant effects of MDMA suggests a role for the mesolimbic dopamine system. Destruction of dopamine terminal fields in the nucleus accumbens significantly attenuated the locomotor activation produced by MDMA. A similar blockade of amphetamine-induced locomotor hyperactivity is known and was observed following amphetamine injection in these same rats. Such results support the hypothesis that at least one component of MDMA-induced hyperactivity is dopamine mediated and suggest that mesolimbic dopamine specifically is the critical substrate. In this way, MDMA resembles other classical psychostimulants like amphetamine and cocaine. Interestingly, evidence for functional cross-sensitization was suggested in the study in which an injection of amphetamine followed MDMA injection. 

Stimulant), act directly on dopamine transmission. Both cocaine and amphetamine block reuptake of dopamine, which means that more dopamine is available to activate postsynaptic receptors. Due to the links between excessive dopamine and schizophrenia, it comes as no surprise that the use of cocaine, amphetamine, and similar drugs such as crack (a form of cocaine) often lead to symptoms strongly resembling schizophrenia. 

Several lines of evidence show that dopamine (DA) is implicated in the mediation of some obsessive-compulsive behavior. Animal studies demonstrate that high doses of various dopaminergic agents, such as amphetamine, bromocriptine, apomorphine, and L-DOPA, induce stereotyped movements in animals, which resemble compulsive behaviors in OCD patients. Increased dopaminergic neurotransmission may be responsible for this. Human studies consistently report that abuse of stimulants such... 

MDA-like compounds—such as the TMAs, DOB, DOET, DOM, MMDA, PBR, TMPEA, DMPEA, DMA, PMA and MED A—have molecular structures that resemble mescaline, dopamine and amphetamine. Moreover, the effects are often experienced as being like an interplay between mescaline and amphetamine—one or the other tendency predominating according to the structure of the particular compound. Thus this cluster often has been referred to as "psychedelic amphetamines. (A chemist would probably designate them as "alpha-methyl phenethylamines, "indolealkylamines or "one-ring substituted amphetamines. )... 

Bupropion (amfebutamon) shows structural similarity with amphetamine (p.329) and inhibits neuronal reuptake of dopamine and norepinephrine. It is supposed to aid smokers in kicking the habit, possibly because it evokes CNS effects resembling those of nicotine. The high relapse rate after termination of the drug and substantial side effects put its therapeutic value in doubt. 

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