Psychophysiology Lecture #3 Flashcards
What are the 2 major aspects of drug influence?
- Drug Effects: observed changes
- Sites of action: drug molecule binding sites –> must reach the site before able to affect bx.
What does the body do to drugs?
A: absorption
D: distribution
M: metabolism
E: excretion
ADME
How many liters of blood is pumped every minute?
5
How long does it take the entire volume of blood supply to circulate?
1 minute.
Inhalation vs. Insufflation
Inhalation = lungs
Insufflation = nasal passage
Intravenous
Fastest and most dangerous.
- 30-60 seconds.
What role does the kidney play in metabolizing and excreting drugs?
Primary organ of excretion
What role does the liver play in metabolizing and excreting drugs?
Active role in enzymatic deactivation.
Dose-Response Curve
Point of maximum effect.
Effectiveness of drug is impacted by?
- Sites of action.
- Affinity of a drug from its site of action.
Affinity
The capacity of a drug molecule to bind to a key site of action.
What does the most desirable drug have?
High affinity for sites of action producing therapeutic effects and low affinity for sites of action producing toxic side effects.
Effective vs. Toxic Dose
- Effective Dose: 50 (ED50)
- Toxic Dose: 50 (TD50)
Therapeutic Index
A quantitive measurement of relative safety of a drug.
- Lower ratio = more dangerous.
- Ideal TI >10
Neurotransmitters
A chemical used for neuron-to-neuron communication.
- Stored in presynaptic neuron.
- Released into synaptic cleft.
How are neurotransmitters terminated?
- Reuptake
- Enzymatic
- Deactivation/degradation
Neuromodulator
A chemical that affects the neurotransmission of a whole group of neurons.
Agonist
A molecule that by binding to the receptor stimulates a response = increase in postsynaptic effect.
Antagonist
A molecule that by bind go to a receptor blocks or inhibits the response = decrease postsynaptic effect.
Amino Acid Neurotransmitters in the brain
- Excitatory: Glutamate
- Inhibitory: Gamma-Aminobutyric Acid (GABA)
Amino Acid Neurotransmitters in the spinal cord and lower brain stem
- Excitatory: Glutamate
- Inhibitory: Glycine
Glutamate
“Go”
- Main excitatory neurotransmitter in the brain and spinal cord.
What are the 4 main receptors in glutamate?
- NMDA: long term potential
- AMPA : effect sodium channels.
- Kainate: effect sodium channels
- Metabotropic Glutamate: presynaptic auto receptor.
NMDA Receptor
- 6 Binding sites
- When channel is open NMDA receptor allows sodium and calcium into the cell –> depolarization.
