Substance Abuse Flashcards
Where do drugs release dopamine?
nucleus accumbens (NAC)
what part of the brain does drug use start causing long-term changes in?
ventral tegmental area (VTA)
what system in the brain does addiction begin in?
mesolimbic dopaminergic system
what changes occur in the VTA and what does this mean in reference to addiction?
increased strength of the excitatory synapses on dopaminergic neurons in the VTA a single administration of an addictive drug
Changes in the VTA lead to increased activation in a variety of regions that receive dopaminergic input from the VTA.
What do changes in the basal ganglia have to do with addiction?
play a role in instrumental conditioning
how does drug-related stimuli influence the brain?
dopamine increases in the nucleus accumbens/dorsal striatum in response to drug-related stimuli
what role does the pre-frontal cortex have in addiction?
addicts show abnormalities in the connectivity, PFC plays an important role through emotion regulation and inhibitory control
how do stimulants work?
Cocaine: deactivates dopamine transporter proteins,
blocking the reuptake of dopamine
Amphetamine: also inhibits the reuptake of dopamine but directly stimulates the release of dopamine from terminal buttons as well
what part of the brain is associated with nicotine addiction?
insula - those with insular damage were better at quitting smoking
which 2 receptors are the main action sites for alcohol in the brain and what do they do??
– Indirect antagonist at NMDA receptors (glutamate -intrinsic to addiction)
– Indirect agonist at GABAA receptors (anxiolytic and sedative effects)
how does alcohol interact with opiates/opiate receptors in the brain?
Alcohol can trigger the release of endogenous opioids
The level of opioid receptors increases with abstinence and is thought to be related to cravings for alcohol
what is the main symptom for Korsakoff’s syndrome?
lack of new memories after a certain age
What is the biology behind Korsakoff’s syndrome?
Caused by interaction of alcoholism & malnourishment. Damage to areas of the thalamus and the mammillary bodies- structures important for encoding new memories.
does environment or nature play a stronger role in the chances of developing addiction?
environment plays a stronger role in drug use but genetics play a stronger role in determining whether the person becomes addicted
what is the genetic attribution of vulnerability to addiction?
40-60%
