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10 Cards in this Set
- Front
- Back
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what are the types of cell-cell communitcation
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paracrine (cell releases a signal into the interstitial fluids and diffuses nearby and the chemical binds to a nearby cell ),
endocrine (cell releases a signal into the blood stream, bathes all the bodies tissues but only binds to cells that have a receptor for it), gap junctions- cells in direct connection, action potential in one causes action potential in other, autocrine (signal binds to the cell that released it) is a form of negative feedback neurotransmission- |
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what are the major neurotransmitter system?
How are they limited in the synaptic cleft? |
Cholenergic-acetylcholine (destruction of the NT by NZ's)
Adrenergic- dopamine, nonepinephrine, epinephrine, histamine, serotonin (reuptake, protein takes NT back to presynaptic cell where SNAP VMAP proteins sequester and package it Excitatory Amino Acids- Glutamate and or asparatate (Uptake) Inhibitory Amino Acids-glycine (spinal cord, brainstem) GABA-higher CNS |
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what are the 3 stages of a neurotransmitter before release
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synthesis in the soma, transport to the synaptic terminal, packaging of NT (vesicular transport protein), congregation of vesicles in "active zones" of presynaptic terminal. (docking and priming (ATP))
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how is the neurotransmitter released
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calcium voltage gated ion channels are opened by the action potential allowing Ca+ in, Ca+ then binds to or associates with docking proteins (SNAP and VAMP (synaptobrevin is an integral membrane protein of the vesical)) which essentially become a bridge to pull the vesicle to the membrane. the NT vesicles merge with the pre-synaptic membrane and makes a fusion pore using SNAP proteins and releases NT's into the synaptic cleft through exocytosis
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After the NT has diffused across the synaptic cleft what mechanisms can get rid of it?
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1. Diffuse away, this is limited due to the anatomy of the synaptic cleft
2. Natural degradation/proteins: only works on a few NTs 3.Enzymatic destruction: NZ in the synaptic cleft destroys the NT (Ach) 4. Reuptake: transport protein will take the NT back to the presynaptic terminal |
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what types of responses can happen when a NT binds to a post synaptic receptor?
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1. activate a second messenger system
2. open a ligand gated ion channel |
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what the difference b/t the ion channels on the dendrites and soma vs. ion channels at the axon hillock
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channels on the dendrites/soma are ligand gated, they can't produce an action potential
axon hillock channels are voltage gated not ligand and produce an action potential |
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what is an EPSP?
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excitatory post synaptic potential, occurs when Ca+ or Na+ channels are opened, it is local, graded, dies away with distance and time
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what is an IPSP?
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inhibitory post synaptic potential, occurs when Cl- gated channels are opened, chloride enters the dendrite causing a hyperpolarization
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what is summation?What are the types?
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happens b/c IPSP and EPSPs are graded so they can add together
temporal (time)- happen within a short period of time so the second one arrives at the hillock before the first potential has dissipated spatial- happens at the same time at different points on the dendrites of soma. can be positive or negative |
