Compare and Contrast how Cocaine, Ecstasy, Heroin and Cannabis Work in the Brain

Drugs of abuse, such as cocaine, ecstasy, heroin and cannabis, are of natural or synthetic origin, which can alter the emotional state, perception, body functioning and behaviour of an individual. Drugs are known to work in the brain by activating certain brain circuits via different mechanisms, and stimulate or inhibit different neurons in the pathway. However, due to the effects of each drug being different, a drug will affect either different pathways and neurons in the brain to that of another, or through a different process, i.e. direct or indirect activity. This essay will discuss the different mechanisms of action that cocaine, ecstasy, heroin and cannabis have in the brain, in terms of their similarities and dissimilarities. Recent studies are also discussed in relation to such theories, with findings of research having been derived from both humans and animals.

Ecstasy and cocaine are psychostimulants that temporarily increase alertness and awareness. They both act as ‘indirect agonists’, which increase neurotransmitter binding to receptors in the synapse. By binding to the transporters that normally remove the excess of these neurotransmitters from the synaptic gap, ecstasy and cocaine prevent them from being reabsorbed by the neurons that released them, and therefore increase their concentration in the synapses. Changes in the activity of serotonin, dopamine and noradrenaline neurotransmitters in the brain are believed to occur when cocaine (Karch, 2007) and ecstasy (Liechti & Vollenweider, 2001) are used.
Although research has shown that cocaine and ecstasy affect the brain in similar ways by stimulating the release of neurotransmitters and preventing their reuptake, the extent to which the different neurotransmitters are involved in the effects of each drug differs.