Term
| what is synaptic transmission? |
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Definition
| electrical signals sent or transmitted from one neuron to another |
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Term
| T/F synapses can only be electrical. |
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Definition
false
be both electrical or chemical but our focus is chemical |
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Term
| T/F the average neuron forms and receives 1000 synaptic connections and the brain contains 10^11 neurons. |
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Definition
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Term
| what separates the pre and post synaptic neurons? |
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Definition
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Term
| how are ribosomes transported to the terminal branch? |
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Definition
| on the microtubules in vesicles |
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Term
| when does exocytosis of the neurotransmitter being? |
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Definition
| when Ca++ voltage gated channels open and triggers SNARE complex |
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Term
| how does exercise enhance the process of synaptic transmission? |
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Definition
| by increasing the number of mitochondria in the terminal branch because it is an energy dependent process |
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Term
what is a Gray's type 1 synapse?
how are they characterized? |
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Definition
excitatory
the membrane on the post-synaptic side is thicker than the presynaptic membrane |
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Term
what is a Gray's type 2 synapse?
how are they characterized? |
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Definition
inhibitory
the pre and post-synaptic membranes are the same thickness |
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Term
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Definition
| the discharge of a single synaptic vesicle releases thousands of neurotransmitter molecules |
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Term
| outline the steps in neurotransmitter release. |
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Definition
1-AP arrives at the axon terminal
2-depolarization causes the voltage-gated Ca++ channels to open
3-Ca++ causes exocytosis to occur in the vesicles that are "docked" at active zones (SNARE complex)
4-vesicle membrane later recovered by endocytosis |
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Term
| what are the two functional domains for ligand gated and metabotropic receptors? |
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Definition
extracellular site to bind neurotransmitters
ion channel |
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Term
| how do metabotropic receptors work? |
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Definition
| they affect channels by the activation of intermediate molecules called G-proteins |
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Term
| T/F ligand receptors are faster than metabotropic receptors. |
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Definition
|
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Term
| what happens when a neurotransmitters binds to a ligand gated ion channel? |
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Definition
closed otherwise
when a neurotransmitter binds to the receptor by a specific site on the extracellular region, a slight change results in the pore opening. |
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Term
| when Na+/K+ enters the cell it causes a depolarization, which is excitatory. |
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Definition
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Term
| what is an Excitatory Post-Synaptic Potential (EPSP)? |
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Definition
| a transcient post-synaptic membrane depolarization caused by the release of neurotransmitters |
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Term
| what is an Inhibitory Post-Synaptic Potential (IPSP)? |
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Definition
| a transcient hyper polarization of the post-synaptic membrane |
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Term
| how many binding sites are on the post-synaptic Ach receptor? |
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Definition
| 2 sites that oppose each other |
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Term
| what are the three steps in a G-protein coupled receptor? |
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Definition
1-neurotransmitter binds to protein embedded in the plasma membrane
2-receptor protein activates small proteins called G-proteins (alpha subunit), which can move along the intracellular face of the post-synaptice membrane
3-G-proteins activate effector proteins (either ion channels or enzymes to synthesize 2nd messengers |
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Term
| what are the four steps of the second messenger? |
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Definition
1-agonists activates membrane bound receptor
2-G-protein is activated and produces effector
3-effector stimulates 2nd messenger synthesis
4-2nd messenger activated intercellular process |
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Term
| how many and name the subunits on the G-protein? |
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Definition
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Term
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Definition
| a process by which cells absorb molecules by engulfing them |
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Term
| what is the endocytic pathway (EP)? |
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Definition
| includes membrane compartments that internalize molecules from the plasma membrane and recycle them back to the surface or sort them to degradation |
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Term
| what are the steps of endocytosis once the vesicle releases the neurotransmitter into the synaptic cleft? |
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Definition
1-the presynaptic membrane forms a bud surrounded by clathrin.
2-the bud is pinched off (can be filled with a neurotransmitter or passed to early endosome)
3-the process of exocytosis occurs again |
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Term
| outline the steps from exocytosis to endocytosis to transmit an electrical impulse. |
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Definition
1-Na+ and K+ channels open along the axon to move the AP down the axon, meanwhile vesicles are waiting in the terminal branch
2-vesicles move along the microtubules from the cell body to the axon terminal (no microtubules in the axon terminal)
3-the SNARE complex is formed when a vesicle nears an active site on the presynaptic membrane, the protein attaches to the vesicle and "docks" it on the membrane at the active site
4-as the AP reaches the axon terminal, the Ca++ voltage gated ion channels open and allow for an influx of Ca++
5-Ca++ binds to the SNARE complex and begins the fusion of the plasma membrane and the vesicle to release the neurotransmitter (exocytosis)
6-After the neurotransmitter is released into the synaptic cleft, the protein clathrin surrounds the vesicle membrane
7-the vesicle membrane is pinched off
8-at this point the vesicle can be refilled with neurotransmitters or sorted into degradation to be made into a new vesicle
9-the process begins again |
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Term
| what recycles the vesicle after exocytosis? |
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Definition
|
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Term
| how is glutamate recycled after exocytosis? |
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Definition
| uptake by an astrocyte breaks it down with glutamate synthetase and returns glutamine to the neuron |
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Term
| how is Ach recycled after exocytosis? |
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Definition
1-Ach is released into the synaptic cleft
2-Acetylcholinesterase(AchE) degrades Ach to choline and acetic acid
3-Choline is taken up by the neuron to be made into Ach |
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Term
| T/F the binding of Ach to the post-synaptic muscle cell causes the opening of both Na+ and K+ channels. |
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Definition
|
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Term
| outline the steps of diffusion across the synaptic cleft of Ach. |
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Definition
1-Ach is released from the presynaptic membrane by exocytosis
2-Ach diffuses across the synaptic cleft and binds to a Ach receptor on the post-synaptic membrane (2 sites)
3-Ach causes the Na+ and K+ channels to open
4-electrical impulse is transmitted to the post-synaptic neuron and the depolarization process begins all over again |
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Term
| what is the Patch Clamp experiment technique? |
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Definition
a glass pipet is fit to surround a single Ach receptor
neurotransmitters are released into an saline solution to observe the effects of the receptor |
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Term
| where is the GABA neurotransmitter synthesized? |
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Definition
| the cells that use it as a neurotransmitter |
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Term
| what is GABA used for and where is it found? |
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Definition
| widely distributed in the brain and serves as a means for synaptic inhibition |
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Term
| what are amino acid gated channels important for? |
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Definition
| sensory systems, memory, and disease |
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Term
| what two glutamate-gated channels handle most of the fast synaptic transmission in the brain? |
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Definition
|
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Term
| what is AMPA permeable to? |
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Definition
|
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Term
| what is NMDA permeable to? |
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Definition
| Ca++ and is voltage gated |
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Term
| NMDA receptors activate neurons that are associated with what? |
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Definition
|
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Term
| what is spacial summation? |
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Definition
| multiple synapses of a dendrite that are individually not threshold, but when combined reach threshold |
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Term
| what is temporal summation? |
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Definition
| increase the frequency of signals/stimulus and threshold will be reached |
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Term
| what needs to bind to NMDA receptor for it to become active? |
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Definition
|
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Term
| what does the binding of glutamate and glycine to a NDMA receptor cause? |
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Definition
| causes Ca+ to move into the cell and cause cell signaling |
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Term
| EPSPs move to/away from threshold. |
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Definition
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Term
| IPSPs move to/away from threshold. |
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Definition
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