Substance-Related Disorders Flashcards
Define addiction
a condition that results when a person ingests a substance (e.g. alcohol, cocaine, nicotine) or engages in an activity (e.g., gambling, sex, shopping) that can be pleasurable but the continuation of which becomes compulsive and interferes with ordinary responsibilities and concerns, such as work, relationships, or health
What areas of the brain involved in the dopamine pathways involved with reward, pleasure, euphoria, motor function, and decision making?
- Prefrontal cortex
- Hippocampus
- Nucleus accumbens
- Ventral tegmental area***
- Raphe
What are the areas of the brain involved in the serotonin pathways involved with mood, memory, sleep, cognition?
- Prefrontal cortex
- Hippocampus
- Nucleus accumbens
- Ventral tegmental area***
- Raphe
What activities and substances may activate the reward pathways in the brain?
- food
- water
- sex
- activities (such as sky diving, roller coasters, etc.)
- exercise
What are the 4 neurotransmitters acting on the reward pathway
- dopamine
- serotonin
- cannabinoids
- opioid peptides (endorphins, enkephalins)
Dopamine
- receptors
- function
- receptors: D1, D2
- function: pleasure, euphoria, mood, motor function
Serotonin
- receptors
- function
- receptors: 5HT3
- function: mood, impulsivity, anxiety, sleep, cognition
Cannabinoids
- receptors
- function
- receptors: CB1, CB2
- function: pain, appetite, memory
Opioid peptides (endorphins, enkephalins)
- receptors
- function
- receptors: Kappa, Mu, Delta
- function: pain
Name the final chemical activator in the reward pathways.
Dopamine!
Neurotransmitter’s anatomical sites
-dopamine
- ventral tegmental area
- nucleus accumbens
Neurotransmitter’s anatomical sites
-opioid peptides
- nucleus accumbens
- amygdala
- ventral tegmental area
Neurotransmitter’s anatomical sites
-GABA
- amygdala
- bed nucleus of stria terminalis
Neurotransmitter’s anatomical sites
-glutamate
-nucleus accumbens
MOA of cocaine to facilitate dopamine activity in the CNS
- via reuptake inhibition of dopamine
- dopamine release is promoted via the protein responsible for the reuptake of dopamine (dopamine transporter; DAT)
*an example of direct drug action
Action of alcohol in reward pathway
inhibit GABAergic neurons that project to dopaminergic neurons in the VTA
Action of heroin in reward pathway
binds to opioid receptors that inhibit GABAergic neurons that project to dopaminergic neurons in the VTA
Action of cocaine in reward pathway
blocks the function of DAT (by binding to the DAT and slowing transport)
Action of nicotine in reward pathway
activates cholinergic neurons that project to dopaminergic neurons of the VTA
What are the the 4 changes observed in the CNS after abrupt withdrawal of a substance that has produced tolerance?
- disturbance of the autonomic nervous system
- activation of the thalamus
- release of corticotrophin releasing factor (CRF)
- activation of the locus coeruleus (LC)
What system mediates affective and somatic symptoms of drug withdrawal?
Corticotrophin Releasing Factor (CRF) system
Name the physiological changes observed during drug withdrawal.
the patient feels dysphoric, irritable, depressed, and angry
What are the symptom(s) mediated by dopamine when intoxicated by a drug of abuse?
euphoria
What are the symptom(s) mediated by opioid peptides when intoxicated by a drug of abuse?
- analgesia
- relaxation
