what are the different types of neurotransmitters?
- Acetylcholine
- Monamines (Dopamine, norepinephrine, epinephrine)
- Amino Acids (glutamate, GABA)
- Peptides (Endorphins, substance P)
where are peptide neurotransmitters made/transported to?
they are made in the soma and transported to the presynaptic terminals and waiting to be released
how can neurotransmitters inactivate/go away?
- re-uptake to presynaptic terminal (recycled)
- degraded by enzymes, deactivation (can no longer bind to receptors and cause electrical signal)
- diffusion (neurotransmitters disperse/drift away, no longer in synaptic cleft)
- absorbed by glial cells
what are the 2 types of ion channels
- ionotropic receptor: NT has direct action on ion channels
- metabotropic receptor: NT has indirect action on ion channels
what to know about ionotropic receptors
- nt binds to receptor
- causes ion channel to open up
- allows flow of ions across membrane
important for sensory and movement in order to adapt to environmental stimuli
nt has a direct action on ion channels
how does hyper-polarization occur in ionotropic receptors
K+ channels open and the ions leave the cell, causes inside of cell membrane to be more negative (hyper-polarization)
OR
Cl- ions are outside so when the channels open and the ions flow into the cell which causes the cell to be more negative (hyperpolarization)
what to know about metabotropic receptor
once NT binds to metabotropic receptor there are no direct ion channels for ions to flow through
once NT binds it causes to signal to be released and activates G-protein and triggers 2nd messenger
2nd messenger signals ion channel further down membrane that allows ions to close/flow in
what is a depolarizing NT in metabotropic receptors?
glutamate “excitatory NT”
what is a hyperpolarizing NT in metabotropic receptors?
GABA (inhibitory)
what is a drug?
qny substance that alters biological functions when taken into body by interacting with receptors/biological pathways
what is a psychoactive drug?
any substance that alters brain function and
results in altered mood, perception, consciousness, or behavior
what is the most used psychoactive drug in the world
caffeine
what are the 2 ways drugs affect neurons?
Agonist and Antagonist
what is an agonist
binds directly to and activates a receptor, mimics or increases the effect of a NT
what is an antagonist
binds directly to, but does NOT activate a receptor;
blocks or decreases the effect of a NT
which 3 drugs can cause overdose deaths
alcohol, nicotine, opioids
