The human brain is a highly complex network of specialised cells that interact in an coordinated manner with each other in order to support us with the tools we need not only to survive, but to live a happy and fulfilled life. Using electrical and chemical signalling, information is passed on from one cell to the other (called neurotransmitters) to bridge the gap between one nerve cell to the other (called synaptic cleft). In the cell itself, information is transmitted by the support of an electrical current in the outer layers of the cell.
How drugs affect ‘normal’ brain function
Taking drugs interfere with these processes. In particular, the so-called reward circuit of the brain — which is responsible for emotion, motivation and the continuation of actions that induce feelings of pleasure — is vulnerable to change. A normally functioning reward circuit reinforces life-sustaining activities such as eating and socialising. However, drugs can manipulate this pathway to encourage further drug use which, in turn, could become addictive behaviour. There are at least two ways that drug use disrupts communication in the nerves: These include:
Direct pathways — neurotransmitters (mainly dopamine) are constantly being released at the synaptic cleft, so that nerves are not able to rest between messages. This is the case when for example substances like cocaine or methamphetamine are used.
Indirect pathways — neurotransmitters other than dopamine are blocked from being sent across synaptic clefts, due to the way the drugs mimic and, therefore, compete with other necessary neurotransmitters. Thus, with drugs such as marijuana or heroin, there is an increased amount of dopamine available for sending messages through the body.
Either scenario results in overstimulation of the brain’s reward circuit with dopamine. So instead of a normal response to natural behaviours, the nervous system is ‘flooded’ with the dopamine, producing euphoric effects. This process sets a reinforcing pattern in motion, teaching the brain and body to repeat the rewarding behaviour of abusing drugs.
Article: Medicalwriters.com GmbH