The Brain; four pounds and several thousand miles of unified nerve cells that control every thought, emotion, sensation and movement. Within the brain and spinal cord there are ten thousand distinct varieties of neurons, billions of supportive cells, and a few more trillion synaptic connections, a hundred chemical regulation agents, miles of minuscule blood vessels, axons ranging from a few microns to well over a foot and a half in length. Even with all these pieces of the brain, the place that is affected the most from drug abuse is the frontal lobe.
The frontal lobe is an area in the brain of vertebrates located at the front of each cerebral hemisphere. Frontal lobes are positioned in front of the parietal lobes. Frontal lobes have been found to play a part in impulse control, judgment, language, memory, motor function, problem solving, sexual behavior, socialization and spontaneity. Frontal lobes also assist in planning, coordinating, controlling and executing behavior. Cognitive maturity associated with adulthood is marked by related maturation of cerebral fibers in the frontal lobes between late teenager years and early adult years. This is why drug abuse by teens in these developing years can seriously hinder the maturation of the frontal lobe. The reason that drug abuse affects this particular part of the brain is because this is where the dopamine is stored and where the "reward system" is.
Dopamine is critical to the way the brain controls our movements. Shortage of dopamine may cause Parkinson's disease, in which a person loses the ability to execute smooth, controlled movements. It also controls the flow of information from other areas of the brain. But, in relation to the pleasure system, it provides feelings of enjoyment and reinforcement to motivate us to do, or continue doing, certain activities. Dopamine is released by naturally-rewarding experiences such as food, sex, use of certain drugs and neutral stimuli that become associated with them.
Certain drugs, however, produce different effects on the dopamine process. Cocaine, for example, acts as a dopamine transporter blocker, competitively inhibiting dopamine uptake to increase the lifetime of dopamine. On the other hand, most amphetamines act as dopamine transporter substrates to competitively inhibit dopamine uptake and increase the dopamine efflux using a dopamine transporter. However, some scientists are breaking new ground by proposing the theory that drug addiction might not have everything to do with the "reward" system of dopamine.
"We now know that many of the drugs of abuse target not just those aspects of the brain that alter things like emotion, but also areas that affect our ability to control cognitive operations," says Herb Weingartner of the Division of Neuroscience and Behavioral Research at the National Institute on Drug Abuse. These new studies could shed light into the reason why only some drug users become addicted and also why it's so easy for drug users to relapse even when they have been sober for quite some time. "Science increasingly suggests that brain development is ongoing during adolescence and into the early twenties, and that drug experimentation during this time is more risky to the still-developing brain than previously believed," McLellan said. "Very worrisome is the possibility that drug use during these neurologically formative years may inhibit the critical processes that nurture brain development to its conclusion." But, like all things, different drugs have different effects on the brain.
Hallucinogenic drugs, for example, present some of the most...