Lecture 4 (DONE) Flashcards
GENERAL OVERVIEW OF NEURAL COMMUNICATION
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What open and closes ion channels?
- NT-gated
- Stimulus-gated (senses)
Do sensory systems have dendrites? If not, what is the alternative?
No dendrites. They have ion channels that open and close, but by a gated stimulus.
What are the 4 NT types?
Acetylcholine, monoamines, amino acids, and peptides.
What are the NT amino acids?
GABA and Glutamate
What are the NT peptides?
endorphins and substance P
How do NT “go away?”
a. re-absorbed by pre-synaptic terminals
b. altered to be inactive
c. float away and be absorbed by glial cells
How are NT altered to be inactive?
-broken down by enzymes
-converted into inactive state by enzymes
What is the difference between Ionotropic and Metabotropic receptor? IDMI
I: Direct action on ion channels
M: Indirect action on ion channels
What is an ionophore?
Receptor + Ion Channel
What happens to an ionophore when an NT binds to a receptor?
Change in configuration, which opens up the ion channel
Define depolarizing NT.
Binds to ionophores with Na+ channels and opens them.
What is glutamate and what does it do?
Attaches to ionophores with na+ channels and makes a excitatory NT
What does a hyperpolarizing NT do?
Binds to ionophores with K+ and opens them,
Why hyperpolarizing NTs?
To make inside of neuron more negative when there are too many K+ ions. Down the conc. gradient.
Define “inhibitory NTs”.
GABA attaches to ionophore with Cl- channels
What is another word for a metabotropic receptor?
2nd messenger
What does a metabotropic receptor do?
- Trans. molecule attach to R
- R bends, releases G protein
- G protein alters metabolic pathway and turns on gene to open or close ion channel type.
Indirectly opens
What are the 4 major receptor types?
Ach, Norphenephrine, Dopamine, and Seratonin.
Define drug.
Medicine or other substance that has a physiological effect when introduced to the body
Define psychoactive drug.
any substance that changes brain function and results in altered perception mood or consciousness.
Define agonist.
Mimic or increase the effect of NT.
Define antagonist.
Block or decrease effect of NT.
5 ways drugs can be an agonist
- Stimulate Receptor / Mimic NT
- Stimulate to release more NT
- Block re-absorption of NT at synapse
- Precursor for NT
- Inactivate enzyme that breaks down NT.
