Receptor Potential vs. Postsynaptic potential Flashcards
(26 cards)
Name the two different types of potentials discussed.
- ) Receptor (Generator) potential
- ) Postsynaptic potential
Both potentials are graded changes of what?
Membrane excitability
–that decay away from the site of stimulation
Each membrane potential must be at some threshold at what point of the axon?
Initial segment that contains the voltage gated channels
–Axon hillock
What are the two possible mechanisms of influencing the post synaptic cell?
- ) Ionotropic
- ) Metabotropic
Define ionotropic.
Receptors are localized with actual ion channel
Define metabotropic
Receptors are located at somepoint along the membrane but activiate an ion channel some distance away via a 2nd messenger system
Metabotropic mechanisms requre what?
Physiological changes
—Requrires some internal cellular mechanism that can be long acting via changes in enzyme/protien expression
What protein is directly related to metabotropic mechanisms?
G-protein-coupled receptors
Which receptor type is faster? Ionotropic or Metabotropic
Ionotropic
Examples of ionotropic excitatory neurotransmitters are?
- ) ACh
- ) Glutamate
- ) Ephinephrine
What are examples of ionotropic inhibiotry neurotransmitters?
- ) GABA
- ) Glycine
Neuropeptides are all what type of receptor? Ionotropic or Metabotropic?
Metabotropic
Define neuropeptides
Complex AA peptides from small to large
List examples of Neuropeptides/Neuromodulators
- ) Enkephalin
- ) Calcium Binding Protein
- ) Substance P
List non-traditional neurotransmitters
- ) Nitric oxide
- ) Eiconasoids (Prostaglandins, cannabinoids)
Name the 3 classes of compounds reagarding neurotransmitters
- ) Fast Neurotransmitters
- ) Neuropeptides
- ) Non-traditional Nuerotransmitters
What type of cells can Non-Traditional neurotransmitters affect?
Adjecent cells
Neurotransmitters are co-localized with what?
Neuropeptides/Neuromodulators in axonal terminals
What do Neuromodulators/Neuropeptides do?
Influence receptors/channels rather than result in channeling opening
When dealing with colocalization peptides act as what?
Neuromodulators by modifiying the activity of the cell during neurotransmission, as well as prolonging activity
Give an example of co-localization
GABA colocalizing with calcium binding protiens
GABA/calbindin in the frontal lobe v. GABA/paravalbumin in the occipital lobe
Take home: As GABA enters synpatic cleft it’s effect on that dendrite is changed due to the neuropeptide (calbindin, paravalbumin)
It is the ___________ receptor that deterimines the action (excitatory vs. inhibitory) of the neurotransmitter
Posts synaptic receptor
True or False
Fast neurotransmitters are associated with iontropic receptors but can also act on metabotropic receptors
True
Catecholamines act only through what type of receptors? (ionotropic or metabotropic)
Metabotropic