Exam 2 lecture 9 Flashcards
Basal ganglia
-Decision maker of the brain
-Non conscious decision making
-Set of subcortical brain nuclei
Addiction stages
-Intoxication: Drugs are still in body
-Withdrawal: Drugs leave the body but still have a pharmacological effect. transient state
-Preoccupation/anticipation: Long-term effect of drug use changing the wiring of the brain
- amygdala, hypothalamus, ANS
- Hippocampus, amygdala, basal ganglia
Basal ganglia pathways
Go: makes cortex more active
No go: makes cortex less active
Learning
-Dopamine is the strongest signal inducing rewiring of the basal ganglia
Dopamine 1 receptor: excitatory, metabotropic
Dopamine 2 receptor: Inhibitory, metabotropic
Pyshcostimulants
Drugs that increase psychomotor and sympathetic nervous system activity as well as improve alterness and positive mood
Sympathetic nervous system
Fight and flight
Psychomotor activity
-Cortex and frontal lobe
-movement of muscles
Drugs in psychostimulants
-Ephedra
-Amphetamines (Adderall, MDMA, meth)
-Methylphenidate (Ritalin ADHD)
-Cocaine
Pharmacodynamics
-Modulatory neurotransmitter systems: DA, 5-HT, NE
-Psychostimulants increase these in the synapse
Mechanism of action
- Reuptake is inhibited, makes more DA/5-HT/NE present in synapse
- NT storage into vesicles is blocked, NT concentration goes up and leaks into the synapse
EXCEPTION: Cocaine has more storage of NT, and more NT ends up released
Pharmacokinetics
-Absorption: Various routes of administration. Quickest snorted/injection
-Distribution: Gets into brain rapidly as soon as in body
-Metabolism: Cytochrome p450 in liver (if oral, liver first pass effect)
-Elimination: Kidneys/urine
Half life
-Amphetamine: 10 hr
-Methylphenidate: 2 hr
-Khat: 1.5 hr
-Cocaine: 1 hr
Downstream effect
-Physiological effects after sympathetic nervous system is activated
-HR, blood flow etc
Traits of psychostimulants
-Enthusiasm
-Positive
-Energetic
-At high doses, stressed, stereotypical behaviors, sometimes hallucinations from 5-HT
-Low doses stimulate goal-directed behaviors
Intoxication
-Activation of opioid receptors, dopamine increased
Kappa opioid receptors
Withdrawl
-Removal of physiological effects
-Lack of joy/tired
Because of exhaustion of NT and drug tolerance
Preoccupation/anticipation
-A lot of variability
-Longer exposure, more long term effects (addicted)
Experiment in rats
-Low doses of ritalin increase attention
-highdoses overstimulate
