Intro to CNS Flashcards
Neurotransmitter binds to and openion channels
Direct Action
Neurotransmitter act through intracellular second messengers, usually G protein pathways
Indirect Action
Promotes rapid responses byaltering membrane potential
Direct Action
Broader, longer=lasting effects
Indirect
opens and closes in RESPONSE TO VOLTAGE changes across the membrane
Voltage-gated
a hormone, drug or transimitter binds to the protein and the channels opens up
Ligan-gated
Na channels, lidocaine are examples of
voltage gated
glutamate(AMPA), nicotinic ACh receptors are examples of
ligand-gated
Action is immediate and brief
Ionotropic (ligand-gated
Not directly linked to ion channels
Metabotropic
some are excitatory and open channels forsmall cation
Ionotropic
initiates biochemical processes that mediate more long term effects and modify the responsiveness of the neuron
metabotropic
some are are inhibitor and allow Cl influx or K efflux to cause hyprerpolarization
ionotropic
Neurotransmitter acts as the first messenger which activates a second messenger that in turn changes excitability of a neurons
Metabotropic
receptors on an axon terminal through which the neuron’s own neurotransmitter can influence the function of the terminal (usually inhibitory) - for example, D2 receptors
autorecpetor
receptors on an axon terminal through which neurotransmitters from other neuronal types can influence the function of the terminal
heteroreceptor
Catecholamines
dopamine
norepinephrine
epinephrine