Safe from Drugs

Posts Tagged ‘Biology’

Other drugs, like cocaine or methamphetamine, can cause nerve cells to release vast amounts of natural neurotransmitters or can block the normal recycling of these brain chemicals, which is necessary to cut the signal between neurons. This results in a greatly amplified message that ultimately disrupts normal communication patterns

Almost all drugs, directly or indirectly target the brain’s reward system by flooding it with dopamine. Dopamine is a neurotransmitter present in regions of the brain that regulate movement, emotion, motivation and feelings of pleasure. Typically, this system responds to natural behaviors related to survival (eating, spending time with loved ones, etc..), But when it is overstimulated by the drug produces feelings of euphoria. This reaction initiates a pattern that “teaches” people to repeat the behavior of drug abuse.

When a person continues to abuse drugs, the brain adapts to the overwhelming surges in dopamine by producing less dopamine or by reducing the number of dopamine receptors in the reward circuit. As a result, the impact of dopamine on the reward circuit is lessened, thereby limiting the pleasure that the user is able to derive not only drugs but also of things that previously caused him pleasure. This decrease compels the addict to continue abusing drugs in an attempt to make dopamine function back to normal. However, they may now require larger amounts of drugs to raise the dopamine to normal levels early. This effect is called tolerance.

The long-term abuse causes changes in other chemical systems and circuits in the brain. Glutamate is a neurotransmitter that influences the reward circuit and the ability to learn. When drug abuse alters the optimal concentration of glutamate, the brain attempts to compensate, which can impair cognitive function. Drugs of abuse facilitate subconscious learning (conditioned), which makes the user feel uncontrollable desire to use drugs when you see a place or a person associated with them, even though the drug itself is not available. Imaging studies of the brain of drug addicts show changes in brain areas critical to the trial, the decision-making, learning, memory and behavior control. Taken together, these changes can cause the addict to become addicted to drugs, ie the look and compulsive use despite adverse consequences. Read the rest of this entry »