Task 3 Flashcards
synapse
gaps between the terminal buttons at the ends of the axon branch of one neuron & the membrane of another
They can occur on three places: dendrites=Axodendric, Soma= Axosomatic, other= Axoaxomic
Presynaptic membran
The membrane of a terminal button that lies next to the postsynaptic membrane & through wich the Neurotransmitter are released
Postsynaptic membrane
The cell membrane opposite the terminal button in a synapse; the membrane of the cell that receives the message
Synaptic cleft
The space between the presynaptic membrane & postsynaptic membrane contains extracellular fluid through eich neurotransmitter diffuse
Synaptic vesicle
A small hollow structure found in terminal buttons; contains molecules of a neurotransmitter
release zone
A region of the interior of the presynaptic
membrane of a synapse to which synaptic vesicles attach and
release their neurotransmitter into the synaptic cleft.
antagonist
A molecule, usually a
drug, that interferes with or prevents the
action of a transmitter.
agonist
A molecule, usually a drug,
that binds a receptor molecule and
initiates a response like that of another
molecule, usually a neurotransmitter.
ionotropic receptor
A receptor
protein that includes an ion channel that
is opened when the receptor is bound by
an agonist.
metabotropic receptor
A receptor protein that does not contain an ion channel but may, when activated, use a G protein system to alter the functioning of the postsynaptic cell.
degradation
The chemical breakdown
of a neurotransmitter into inactive
metabolites.
reuptake
The process by which
released synaptic transmitter molecules
are taken up and reused by the presynaptic
neuron, thus stopping synaptic activity
axo-dendritic
Referring to a synapse in which a presynaptic axon terminal synapses onto a dendrite of the postsynaptic neuron, either via a dendritic spine or directly onto the dendrite itself.
axo-somatic
Referring to a synapse
in which a presynaptic axon terminal
synapses onto the cell body (soma) of the
postsynaptic neuron.
axo-axonic
Referring to a synapse in
which a presynaptic axon terminal synapses
onto another axon’s terminal.
dendro-dendritic
Referring to a
synapse in which a synaptic connection
forms between the dendrites of two
neurons.
exocytosis
The process by which a
synaptic vesicle fuses with the presynaptic
terminal membrane to release neurotransmitter
into the synaptic cleft.
binding site
The location on a receptor protein to which a
ligand binds.
neurotransmitter-dependent ion channel
An ion channel that
opens when a molecule of a neurotransmitter binds with a
postsynaptic receptor.
x ionotropic receptor
G protein
A protein coupled to a metabotropic receptor;
conveys messages to other molecules when a ligand binds with
and activates the receptor.
enzymatic deactivation
The destruction of a neurotransmitter
by an enzyme after its release—for example, the destruction of
acetylcholine by acetylcholinesterase.
presynaptic inhibition
The action of a presynaptic terminal
button in an axoaxonic synapse; reduces the amount of neurotransmitter
released by the postsynaptic terminal button
presynaptic facilitation
The action of a presynaptic terminal
button in an axoaxonic synapse; increases the amount of neurotransmitter
released by the postsynaptic terminal button
Antagonist
a molecule, usually a drug, that interferes with or prevents the action of a transmitter
