Presynaptic Release of Neurotransmitter Flashcards
What is the structure that is designed to facilitate both transmission and receipt of information between neurons?
Synapse
A ____ neuron will transmit information, that is received by a post-synaptic neuron
presynaptic
A _____ neuron receives information that is transmitted by a presynaptic neuron
Post-synaptic neuron
What kind of synapse utilizes gap junctions to transfer an ionic charge from one neuron to the next?
Electrical Synapse
What kind of synapse has direct connection between neuron but relies on the movement of neurotransmitter filled vesicle to transfer information to the next neuron?
Chemical synapse
Neurotransmitters trigger a response by binding to what?
Post-synaptic receptors
What is an inter-membrane structure that enables direct “electrical” communication between adjacent cells
Gap Junctions
Each cell contributes 1/2 of the gap junction channel called what?
Connexon
Connexons between cells are connected via what?
Hemophilia interactions
_____ are identical protein subunits that compose connexons and are arranged hexagonally around a central pore
Connexins
What triggers the connexins to undergo a conformational change to allow the transfer of signals.
Voltage
PH
Ionic concentration
A _____ neuron will transmit information, that is received by a _____ neuron
presynaptic; postsynaptic
Neurons also communicate via synapses to _____ for motor control and homeostatic regulation.
peripheral effectors
For electrical synapse:
The transfer of information is via _____ flowing across the gap junction
ionic charge
For chemical synapse:
The transfer of information is via a _____ crossing the synaptic cleft and binding to postsynaptic receptors
chemical neurotransmitter
A gap junction is an inter-membrane structure that enables direct “_____” communication between adjacent cells
“electrical”
Each connexon is composed of six identical protein subunits called _____, arranged hexagonally around a central pore
Connexins
Would low PH open or close the channels between the connexins?
Close
Would high Calcium level open or close the channels between the connexins?
Close
For electrical synapses, the transfer of information is via _____ from one neuron to the next through the gap junctions
Ionic currents
Neurons interconnected via gap junctions will collectively be at the same state of activity in terms of ____.
Membrane potential
_____ allows groups of neurons to collectively integrate and process information.
Gap junction
Within the brain which may include interneuronal communications via gap junctions, the transmission of information from one neuron to the next occurs via _____.
Chemical synapses
For ___ synapses, the transfer of information is via specific molecules (neurotransmitters) released from the presynaptic neuron, which function as a LIGAND to stimulate receptors on the postsynaptic membrane
Chemical
What are the two directional flow of information?
Electrical and chemical
“electrical” transmission is along ___.
Axons
“chemical” transmission across _____.
Synapses
What is the directional flow of SENSORY information?
From a peripheral receptor into the central nervous system (sensory)
What is the directional flow of NERVOUS information?
Between neurons (“interneuronal”) within the central nervous system (nervous)
What is the directional flow of MOTOR information?
From the central nervous system to a “peripheral effector” (motor)
____ transmission propagated action potentials along nerve fibers.
Electrical
____ transmission is the transference of the signal from the nerve ending to the next neuron or peripheral effector via a synapse.
Chemical
What is the space called that is between presynaptic and postsynaptic?
Synaptic cleft
Information transfer from the presynaptic nerve ending to receptors along the postsynaptic membrane occurs via a _____ neurotransmitter that is released into the synaptic cleft from the nerve ending.
Chemical
Along _____ membrane, there are receptors which receives the neurotransmitters.
Postsynaptic
Nomenclature creates groups, or families, of related neurotransmitters based upon their _____ structure.
chemical
What are monoamines (biogenic amines) derived from?
A single amino acid precursor
What are the two examples of monoamines?
Tyrosine and tryptophan
Dopamine, norepinephrine, and epinephrine are derived from?
Tyrosine
Serotonin is derived from?
Tryptophan
What is g-aminobutyric acid (GABA) derived from?
Glutamate
What is a primary neurotransmitter in PNS and CNS?
Acetylcholine (ACh)
Synthesis of acetylcholine requires what?
Choline acetyltransferase
Synaptic degradation of acetylcholine requires what?
acetylcholinesterase (AChE)
Postsynaptic receptors are classified as?
Cholinergic
Postsynaptic receptors are classified as cholinergic, what are the two major subgroups?
Nicotinic
Muscarinic
What are the three Catecholamines?
Dopamine, norepinephrine, epinephrine
What is the common precursor for dopamine, norepinephrine, epinephrine?
Tyrosine
postsynaptic receptors are classified as _____.
adrenergic
What are the two major subgroups of adrenergic?
Alpha and beta
_____ is the principle excitatory neurotransmitter within the CNS
Glutamate
___ and ___are the principle inhibitory neurotransmitters within the CNS
Glycine and g-aminobutyric acid (GABA)
A neuron’s “state of activity” is maintained through its response to the _____ that it receives
synaptic inputs
A neuron’s state of activity is viewed in terms of:
-Whether or not it is “___” action potentials.
-When “___”, the frequency at which it “fires” action potentials
Firing; active
A neuron’s state of activity is determined by its _____.
membrane potential
- Signaling from the presynaptic
- the arrival of action potentials at the nerve terminal
- neurotransmitter released from the presynaptic terminal
- ligand-activation of the postsynaptic receptors
These are the four major steps for what?
Transfer of information from presynaptic to postsynaptic neuron
There must be a sufficient concentration of _____ in the extracellular fluid in order for neurotransmitter to release.
calcium
What is the first major step in the process of neurotransmitter release?
mobilization and trafficking of vesicles to the active zone
What is the second major step in the process of neurotransmitter release?
Docking of the vesicle to the axonal membrane at the active zone
What is the third major step in the process of neurotransmitter release?
Fusion of the two membranes (vesicle and axon), leading to neurotransmitter release via exocytosis
Mobilization and trafficking of vesicles to the active zone involves _____.
Synapsins
Several key regulatory proteins must interact with the _____ proteins to cause docking, fusion, and exocytosis
SNARES
What are the two cytoplasmic proteins that binds to SNARE complex causes dissociation in ATP dependent reaction?
SNAP and NSF
