Test 1: NTs Flashcards
Psychopharmacology
Study of the effects of drugs on the nervous system and Bx
Drugs never “create” effects…
They “modulate on-going activity of cells”
Pharmacokinetics
the study of drug absorption, distribution within the body, and drug elimination
Drug absorption
Depends on the route of administration
Drug distribution
Depends on how soluble the drug molecule is in fat and the extent to which the drug binds to blood proteins
Drug elimination
Excretion into urine and/or by inactivation by enzymes in the liver
Intraperitoneal (IP)
Drug administration into the gut (used in lab animals)
Dose-response (DR) curve
Depicts the relation between drug dose and magnitude of drug effect
Therapeutic index
the effectiveness of a drug relative to its safety
(Textbook def: the ratio between the dose that produces the desired effect in 50% of the animals and the dose that produces toxic effects in 50% of the animals
Why do drugs vary in their effectiveness?
sites of action and the affinity of a drug with its site of action
Agonist
Any drug with mimics or potentiates the effect of a particular NT
Full Agonist
Has similar structure and therefore has similar effect as NT
Partial Agonist
Similar enough to bind to receptor but can only open some channels
Antagonist
Drug binds to receptors but has no phamacological properties of its own
Competitive Antagonist
Drug competes for available receptors and displaces NTs
Noncompetitive Antagonist
Interferes with transmission
“Any agonist whose dose is too high can become an ___”
Antagonist
Where do precursors come from?
Diet
How are precursors converted into NTs?
Synthetic enzymes
List 5 actions agonists do
1) Add precursor (dietary supplement)
2) Increase NT (only if it can cross BBB)
3) Block reuptake
4) Block metabolic enzyme
5) Mimetic-Binds to receptor and opens channel like NT
List 5 actions antagonists do
1) Dietary depletion of precursor
2) Block synthetic enzyme
3) Make synaptic vesicles “leaky”
4) Block release of NT
5) Blocking agent (competitive and noncompetitive)
Function of Acetylcholine
- Movement-activates muscle at neuromuscular junction
- Attention
- Arousal
- Motivation
- Learning and memory
- Consciousness and REM Sleep
Where are ACh muscarinic receptors found?
- Heart and smooth muscle
- More abundant in cerebral cortex (Metabotropic receptors)
Nicotinic receptors are found in…
skeletal muscle
3 monoamine transmitters (catecholamines)
Dopamine (DA), norepinephrine (NE), and epinephrine (EPI)
What is the function of dopamine?
- Movement
- Pleasure/reward
- Attention/learning
Are dopamine receptors metabotropic?
Yes
What is a substance that degrades dopamine in the axon terminal?
Monoamine oxidase (MAO)
What are positive symptoms of schizophrenia?
- delusions
- hallucinations
- thought disorder
Incidence rate of schiz?
Gender differences in incidence?
1%.
No gender differences
Negative symptoms of schiz?
- Poverty of speech and low initiative
- Social withdrawal and diminished affect
Dopamine hypothesis
“Positive symptoms of schiz involve overactivity of brain DA synapses”
Revised DA Theory
“Excessive DA transmission in the mesolimbic DA system causes the + symptoms of schiz, while decreased DA transmission in the mesocortical DA system is responsible for the - symptoms”
Hypofrontality
Decreased activity of the dorsolateral prefrontal cortex
Describe how abuse of PCP produces + and - symptoms of schiz
+: related to indirect actions of PCP on accumbens DA
-: related to decreased DA utilization in prefrontal cortex following PCP treatment
