Problem 3 Synapse Flashcards
Presynaptic membrane
The membrane of a terminal button that lies next to the postsynaptic membrane through which the neurotransmitter is released
Postsynaptic membrane
The cell membrane opposite the terminal button in a synapse, the membrane of the cell that receives the message
Microtubule
transport neuropeptides
synaptic cleft
The space between the presynaptic and the postsynaptic membrane
Synaptic vesicle
A small hollow beadlike structure found in terminal buttons, contains molecules of a neurotransmitter; number reaches from dozens to several hundreds (produced in the golgi apparatus and the soma)
Release zone
: A region in the interior of the presynaptic membrane to which the vesicles attach an release their neurotransmitter into the synaptic cleft
Ionotropic receptor
A receptor that contains a binding site for a neurotransmitter and an ion channel that opens when a molecule of the neurotransmitter attaches to the binding site (lets Sodium into the cell and so depolarize the membrane)
Metabotropic receptors
A receptor that contains a binding site for a neurotransmitter; activates an enzyme that begins a series of events that open an ion channel elsewhere in the membrane of the cell when a molecule of the neurotransmitter attaches to the binding site
Autoreceptor
A receptor molecule on a neuron that responds to the neurotransmitter released by that neuron (can be located at any part of the membrane)
tells the cell if there are enough neurotransmitter in the synapse cleft
Amino Acid Neurotransmitter
o majority of fast-acting transmitters in the central nervous system
o glutamate, aspartate (excitatory in spinal cord), glycine, and gamma-aminobutyric acid (GABA)
-small
Monoamineneurotransmitters
o Small molecule neurotransmitter
o Dopamine, epinephrine, norepinephrine (catecholamines)
Noradrenergic
neurons that release Norepinephrine (Noradrenaline)
Adrenergic
neurons that release epinephrine
adrenaline
Acetylcholine
Responsible for muscular junctions (automatic nervous system) (muscular memory)
small
Soluble-gas neurotransmitters
Unconventional Neurotransmitter
At some synapses, they transmit feedback signals from the postsynaptic neuron back to the presynaptic neuron
Regulate the activity of presynaptic neuron
Endocannabinoids
Unconventional Neurotransmitter
Similar to THC
Inhibitory
Neuropeptides
o Consist of 3-36 amino acids
o They are more produced by the soma and transported by the micro tubules
Postsynaptic potential
Neurotransmitter are released after the AP in the postsynaptic cell, can vary in amplitude and spreads passively across the cell membrane
Release of Neurotransmitter
Docking is when the vesicles bind with the presynaptic membrane and this happens when clusters of protein molecule attach to other clusters of protein molecules located in the presynaptic membrane
Fusion of pores
When the Ca2+ binds with the clusters of molecules of the membrane and the vesicles it opens the fusion pore and releases the neurotransmitter
General recycling
Vesicles push the membrane to the site where it starts to fold. These folds are used for the production of vesicles
neurotransmitter-dependent ion channel
An ion channel that opens when a molecule of a neurotransmitter binds with a postsynaptic receptor (permit the passage of certain ions through the postsynaptic membrane which changes the local membrane potential)
excitatory postsynaptic potential (EPSP)
An excitatory depolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button (sodium) increases the likelihood that AP fires
inhibitory postsynaptic potential (IPSP)
An inhibitory hyperpolarization of the postsynaptic membrane of a synapse caused by the liberation of a neurotransmitter by the terminal button (K+) Some open chloride channels as well (serves to neutralize) decrease the likelihood that AP fires
Reuptake
rapid removal of the neurotransmitter from the synaptic cleft by the terminal button. When an action potential arrives, the terminal button releases a small amount of neurotransmitter into the synaptic cleft and then takes it back, giving the postsynaptic receptors only a brief exposure to the neurotransmitter
Enzymatic deactivation
The destruction of Neurotransmitter by an enzyme after its release – for example, the destruction of acetylcholine by acetylcholinesterase
Creation of Neurotransmitter
Neurotransmitter are synthesized from precursors under the influence of enzymes
Leaking Neurotransmitter
getting destroyed by enzymes
Agonist
drugs that facilitate the effects of particular neurotransmitter
o Bind to postsynaptic receptors and activate them
o Drug increases the synthesis of neurotransmitter molecules by increasing the a mount of precursor
o Drug increases the number of neurotransmitter molecules by destroying degrading enzymes
o Increase the release of neurotransmitter from terminal buttons
o Drug binds to autoreceptors an block their inhibitory effect on neurotransmitter release
o binds to postsynaptic receptors an blocks their inhibitory effect on them of neurotransmitter moleucles
o Drug blocks the deactivation of neurotransmitter molecules by blocking degradation or reuptake
Antagonists
drugs that inhibit the effects of particular neurotransmitter
o Blocks the synthesis of neurotransmitter molecules e.g. by destroying synthesis enzymes
o Causes the neurotransmitter molecules to leak from the vesicles and by destroyed by degrading enzymes
o Blocks the release of the neurotransmitter molecules from terminal buttons
o Drug activates autoreceptors and inhibits neurotransmitter release
o Is a receptor blocker; it binds to the postsynaptic receptors and blocks the effect of the neurotransmitter
Receptor blocker
bind to postsynaptic receptors and blocking them so other neurotransmitter cant bind anymore
Inverse Agonist
Inactivates a neuron
Glutamate
- Important role in learning and memory
* Excitatory
GABA
- Regulates communication between brain cells
* Inhibitory
Dopamine
• Voluntary movement, attention, learning, problem solving, associated with reward and reinforcement
Norepinephrine
• Contributes to diverse behavioural and physiological processes, including mood, overall arousal, and sexual behaviour
Serotonin
• Implicated in the control of sleep states, mood, sexual behaviour, anxiety and many other functions
