Synaptic transmission Flashcards
What does presynaptic and postsynaptic neurons do
pre synaptic neurons deliver messages
post synaptic neurons recieves messages
What is temporal summation
several impulses from one neuron over time
What is spatial summation
impulses from several neurons at the same time
What are the 2 different graded potentials at postsynaptic neuron
- excitatory postsynaptic potential (depolarises)
- inhibitory postsynaptic potential (hyperpolarises)
What law do graded potential not follow
all or none law
What is exocytosis
when Ca++ causes vesicles to bind to presynaptic membrane and burst, releasing NT into synaptic cleft
what is the ionotropic effect
NT attaches and immediatley opens ligand gated ions
what is the metabotropic effect
NT attached to receptors slowly
What is the primary difference between an EPSP and an action potential
EPSPs are subthreshold events that decay over time and space.
What is the primary difference between temporal and spatial summation
Spatial summation depends on contributions from more than one sensory neuron
inhibitory synapses on a neuron:
hyperpolarizes the postsynaptic cell
Increased permeability to which ion would most likely result in an IPSP
potassium
What is the sequence of chemical events at a synapse
synthesis, transport, release, reuptake
What is not a catecolamines
seretonin
When an action potential reaches the end of an axon, it evokes the release of neurotransmitters by opening ____ channels in the axon terminal.
calcium
