Chapter 5 Flashcards
(18 cards)
electrical synapses
the current flows through connexons
direct and passive flow of current between neurons
fast, no delay
chemical synapses
allow cell to cell communication through the release of NTs
has a delay in reaction
NT cycle
- synthesis and packaging into vesicles
- release from presynaptic cell
- bind to postsynaptic receptors
- removal or degradation
influx of Ca
triggers the secretion of NTs and causes vesicles to fuse with presynaptic plasma membrane
gap junctions
used by electrical synapses
space between two neurons linked together
contain connexon channels
connexons
provide a channel for electrical current to flow
synaptic transmission
is initiated when APs arrive at the presynaptic terminal which causes membrane potential to change and opens voltage gated Ca channels
EPP
a change in membrane potential that is large enough to produce and AP at a muscle cell
causes muscle fiber to contract
synapsin
reversibly binds to synaptic vesicles and sometimes keeps them tethered within the reserve pool
CaMKII
allows synapsin to dissociate from the vesicles and causes them to be freee
toxins that cleave SNARES cause
a blockage of NT release
ionotropic receptors
aka ligand gate channels
they combine the transmitter binding and channel functions into one
metabotropic receptors
are not ion channels, they are coupled with G proteins
slower compared to other channels
EPPs will depolarize
when the membrane potential is more negative than the reversal potential
EPPs will hyperpolarize
when the membrane potential is more positive than the reversal potential
PSPs are
depolarizing if their reversal potential is more positive than resting potential
and hyperpolarizing if their reversal potential is more negative
EPSPS
Can only depolarize the post synaptic cell
IPSPS
can hyperpolarize or depolarize
