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283 Cards in this Set
- Front
- Back
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name 6 key insights about neuro that were established in the 18 century |
nervous system has a central division consisting of brain/spinal cord bumps and grooves can be seen on the surface of every brain effects of injury to the brain brain talks to body via nerves brain=different parts/functions brain operates like a machine follows law of nature |
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key 4 insights about neuro established end of 19 century |
nerves as wires localization of specific functions tied to different parts of the brain evolution of nervous system neuron as basic functional unit
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what is the neuron doctrine |
neurites of different neurons are not continuous they much communicate by contact not continuity/ nervous system is made up of discrete individual cells
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what does the nissel stain do? |
distinguishes neurons from glial, can see arrangements of different neurons in different areas of the brain, dye stains cell neucli and nissel bodies |
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what does the golgi stain do? |
revealed that neurons have a soma and neurites/cajal worked out curcuitry of regions of the brain and gave rise to the theory (neuron doc) |
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what is the prototypical neuron? |
electrically excitable cell that processes and transmits info through electrical and chemical signaling |
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where does signaling occur |
via synapse |
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what is the soma |
cell body containing cytosol a salty and potassium rich fluid, cytosol holds everything except for nuc |
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what is the nucleus |
control center encolsed by a double membrane, holds chromosomes which hold genetic material, contain DNA blue prints for entire body |
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what is gene expression |
info from gene s used to make proteins |
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how does gene expression process |
DNA-transcription-mRNA-translation-protein |
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when does the DNA leave the nucleus? |
never, info is transferd into the cytoplasm through mRNA |
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what are introns |
genes that cant be used to code for protein (removed trhough RNA splicing) |
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what are extons |
genes that can be used to code for protein |
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the function and structure of rough er |
near nuc, enclosed sacs of membrane with ribosomes, mRNA leaves nuc to go to RER ribosomes to start translations (assembles amino acids to form protein) |
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the function and structure of smoot er |
continuous to rough er, the proteins are folded and given their 3D structure, regulates internal concentrations of substances like calcuim |
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the function and structure of the golgi apparatus |
site of post translational processing of proteins sorts out proteins that need to be delivered to different parts of the neuron |
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structure and function of mitchondria |
cell power plant, generates ATP, site of cellular respiration |
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what is cellualr respiration |
pyruvic acid enters krebs cycle, the biochemical products of krebs provide energy that results in the addition of a phosphate to ADP yielding ATP |
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structure and function of neuronal membrane |
encloses cytoplasm, studded w/ protein, protein pumps, pores, protein composition gives is its function |
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structure and function of the cytoplasm |
in the cytoplasm, made of proteins, present in all cells
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what are the 3 kinds of cytoskeletal fillaments |
microtubules, microfillaments, neurofillaments |
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what is the structure of microtubles |
thick hallow pipe that runs down neurites , made of stands that consist of a protein called tubulin |
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what is the structure of microfilaments |
many in the neurons, stands are a polymers of a protein called actin, it comes together and apart based on neuronal signals |
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neurofillaments |
multiple subunits organized like a chain sausage, each subunit consists of 3 strands of protein coiled tight like a spring, very strong structure |
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what is the axon? |
the end of a neuron specialized for transfer of info (only in neurons) |
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where does the axon start |
@ the hillock |
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how is it different from the soma |
it doesnt have rough er, different protein compostition in the membrane |
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can proteins synthesize in the axon |
no they are synthesized in the soma and transported to the axon |
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what are the individual branches of an axon |
axon collaterals |
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what are the collective branches of the axon called |
terminal arbor |
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what is the then of an axon called |
axon terminal |
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what is the point of contact btwn 2 neurons |
synapse |
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how is the cytoplasm of the axon different from that of the axon terminal |
microtubles dont extend to terminal, terminal has synaptic vesicles, inside surface of the axon terminal membrane has dense covering, axon terminal has many mitchondria |
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the presynaptic side is on the |
axon termial |
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the post synaptic side is on the |
dendrite or soma of another neuron |
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what is the synaptic cleft |
space btwn 2 neurons |
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what is synaptic transmission |
transfer of info across synapse |
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how are most neuronal impulses conducted? |
electrical-chemical (NT release)- electrical |
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where are NT stored |
in synaptic vesicles |
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what is axoplasmic transport? |
cellular process responsible for the movement of mitchondria, lipids, synaptic vesicles,proteins |
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fast axoplasmic transport |
vesicular cargoes move fast 1000 mm per day |
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slow axoplasmic transport |
vasicular cargoes move slow 1-10mmper day |
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what is anterograde transport? |
from soma to terminal material enclosed within vesicles walk down microtubules (legs provided by kinesin and fueled by ATP) |
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what is retrograde transport |
from the axon to the soma (legs provided by dyein), process provides signals from axon to soma about metabolic needs of the terminal |
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what are the dendrites |
branches projections of a neuron that conduct electrochemical stimulation recieved from other neuronal cells to the cell body of the neuron from which the dendrites project |
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what is a dendrite tree? |
antenna of the neuron made of dendritic branches covered in thousand of synapses |
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what are the specialized proteins in the postsynaptic membrane and what do they do |
receptors, they detect NTs in the synaptic cleft |
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dendrites have _ capacity for local protein synthesis and they play a role in determining the extent to which _ are produced by the neuron |
some, AP |
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what do spines of dendrites do? |
increase receptive properties of dendrite to isolate signal specificity, inceases neural activity (leaning) |
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the cytoplasm of the dendrite is like the cytoplasm of the _ because _ |
axon, many mitchondria and cytoskeletal elements |
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how do we classify neurons? |
based on number of neurites, axon length, and NT |
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a unipolar neuron is |
a sensory neuron in the PNS that contains one neurite and an axon with 2 split branches one runs to periphery and the other to the spinal cord |
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bi polar neuron |
2 neurites, known as an interneuron |
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multipolar neuron |
3 or more neurites (most cells in the brain) can be motor neurons or pyramid cells
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how do we classify neurons according to dendrites |
spiny or apinous |
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golgi 1 neurons have |
long axonal processes (pyramid, pukinje, anterior horn) |
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goligi 2 neurons are |
those whose axonal process projects locally |
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collection of neurons that use a common NT make up.. |
NT systems |
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cholinergic neurons |
acetylochin- nicotine receptors |
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GABAergiv neurons |
Gaba is 1 of the 2 neuoinhibitors in the CNS (other is glycine) |
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glutomatergic neuron |
gultamate primary excitatory amino acid |
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dopaminergic neurons |
dopamine connected to mood and behaviour |
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serotonergic neurons |
seretonin can act as excitatory or inhibitory |
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what do glial cells do? |
insulate and support and nourish neurons, form myelin and protect neurons |
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astrocytes are |
glial star shaped cells that provide mechanical and metabolic support to neurons of the CNS, maintain composition of extracellular fluid (regulate postassium) |
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astrocytes contain the NT _ which can be released and activate the _ responsive to _ |
gaba, receptors, gaba |
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Oligodendrocytes are |
myelinating glial that form a sheath around the axons of the CNS |
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what cell is the functional homologue of oligodendrocytes and how do they differ? |
Schwann cells, they work in the periphery not the CNS they dont form myein sheath |
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what does a meylin sheath provide to an axon? |
insulations and allows electrical signals to propagate more efficiently |
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what are microglias |
small cells with complex shapes, delivered form cell line which also gives ride to monocytes |
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where is the electrical charge of a neuron and how is it carried |
in the axon, carried by electrically charged atoms |
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what has the properties that can cause an AP that doesnt diminish over distances and is of a fixed duration and size |
the axonal memebrane |
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cells that can conduct an AP are said to have an |
exictable membrane |
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when an excitable membrane is not generating an AP it is |
at rest |
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what is the charge of the cytosol in the resting neuron? |
-65 mV |
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if the neuron is at rest the inside contains _ charged ions and the outside contains _ charged ions |
negative, postive |
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the resting potential is |
the difference in electrical charge across the membrane |
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the action potential is |
the reversal of the resting potential where the charge inside the membrane becomes positive relative to the outside |
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what are the 3 major components of the RP? |
the cytosol and extracellular fluid the membrane the proteins which inhabit the cell membrane |
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what are cations |
positive ions |
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what are anions |
negative ions |
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how does the cytosol contribute to the RP? |
contains much higher amounts of charged molecules (ions) the outside |
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what are ions |
atoms with an electrical charge held together by oppostitely charged atoms |
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the electrical charge of an ion is a function of |
the difference btwn the number of protons and electrons |
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a monovalent atom has |
a difference of 1 btwn protons and electrons |
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a divalent atom has |
a difference of 2 btwn protons and electrons |
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Na+ and K+ are |
monovalent cations |
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calcium is |
divalent cation |
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chloride is |
monovalent anion |
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when the neuron is at rest, K+ inside the cell is... |
higher compared to the outside |
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when the neuron is at rest the Na+ outside is ... |
higher in comaprison to inside |
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when the neuron is at rest Ca+ in the neuron is .... |
lower in comparison to outsidew |
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when the neuron is at rest the Cl- in the neuron is .... |
low in comparison to outside |
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when the membrane is at rest it doesnt let most ions in except for _ because _ |
K+, bc it is selectively permeable to ions and organic molecules and controls the movement (passive or active) of substances in and out the cell |
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the stable arrangement of a cell membrane is |
the phospholipid bilayer |
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a phospholipid has |
a hydrophobic tail (that excludes water and salt) and a hydrophilic head |
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what provides routes for ions to cross the cell membrane |
the proteins embedded in the membrane (this it what the RP/AP depends on |
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proteinds are made of |
20 different amino acids |
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all amino acids have... |
a central carbon atom bonded by 2 molecular groups |
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how are proteins synthesized? |
ribosomes assemble AA in a chain connected by peptide bonds and carboxyl groups |
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polypeptides are |
proteins made of a single chain of AA |
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what are ion channels made of |
membrane spanning molecules, 4-6 similar protein molecules assemble to form a pore btwn them |
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gating is |
the act of an ion channel opening or closing based on microenvironment |
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ion pumps are |
membrane spanning proteins, enzymes that used energy released by ATP to transport ions across the membrane |
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_ play a crucial role in neuronal signaling by transporting _ and _ from inside to outside the cell |
ion pumps, Na+, K+ |
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how is the ion concentration gradient established? |
by the action of the pump |
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when the neuron is at rest, the sodium ion pump transport _ sodium ions _ and _ potassium ions _ |
3 out and 2 in |
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when the neuron is at rest the concentration of K+ in the cell is _ than outside |
2 times more
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when the neuron is at rest the concentration of Na+ outside the cell is _ |
9 time more than inside |
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when the membrane is at rest, the calcium pump _ Ca+ _ |
actively transports, outside the cytosol across the mem |
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the movement of ions across a channel is governed by |
diffusion and electricity |
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diffusion is |
when particles go from areas of high concentration to low |
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diffusion will cause K+ ions to be pushed through channels in the membrane because |
the membrane is selectively permeable to K+ when the neuron is at rest |
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ions only flow in and out the membrane when |
the channels permit it |
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why doesnt sodium flow into the cytosol when the membrane is at rest? |
channels block sodium inhibiting sodium diffusion |
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when does an electrical force arise? |
a mutual attraction btwn 2 particles w/ opposite charges and a mutual repulsion btwn particles w/ the same charge |
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the diffusion of ions causes |
an electrical potential difference across the membrane that acts in opposite direction of the diffusing force |
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what does no net movement of K+ mean? |
the electrical force counterbalances the diffusion force therefore for ever K+ that leaves, one comes in |
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the RP relies on _ for its maintnance |
expenditure of energy |
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hyperpolarizing means |
the cell becomes more negative (inhibits AP) |
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depolarizing means |
the cell becomes more postitive increasing AP |
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an AP is conducted down the _ when_ |
axon, when the inner membrane is + relative to the outside |
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the information sent from neuron to neuron is encoded in |
the frequency and pattern of AP |
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the AP starts at _ with a _ |
the axon hillock with a strong depolarization |
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depolarization of the axon is caused by |
influx of Na+ through the opening of some Na+ channels |
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What happens if depolarization is small |
outward K+ current overwhelms inward Na+ current and membrane repolarizes back into normal RP |
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if depolarization reaches threashold then... |
AP will be generated |
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AP is caused by |
depolarization of the membrane beyond threshold |
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what is the all or nothing phenomnea |
the fact that AP will only occur once threshold us achieved |
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how do sensory neurons depolarize |
stimuli can cause depolarization by the entry of Na+ through specialized ion channels |
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how do intraneurons depolarize by |
the Na+ entry through channels that are sensitive to NT released by other neurons |
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what is the max frequency which AP can be genereated |
10000 HZ |
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membrane potential is such that the voltage gated Na+ channels open so that the relative ionic permeability of the membrane favours Na+ when... |
the threshold is crossed |
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when does the rising phase occur? |
the inner membrane is negative so the Na+ ions forcefully drive in bc the voltage gated sodium channels are open and depolarize the cell |
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how does the overshoot occur |
inward sodium current increases more than the outward K+ current and a runaway conition |
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during AP, the influx of Na+ ions into the cell causes the cystosol to have a charge of |
+50 mV |
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how does the falling phase start |
The Na+ channels start to close and become inactivated lowering the permeability of Na+ relative to K+ into the cell |
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what is the second contributing factor to the falling phase |
K+ channels oppen (they were triggered to do this b4 the depolarization of the membrane |
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why is there an undershoot |
the raised membrane potential opened a lot more K+ channels than usual and some dont close as soon as the membrane returns to normal volatge |
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what is an absolute refractory period |
period where is is impossible to evoke another AP, when closing after AP sodium channels enter an inactivated state where they cant open regardless of membrane potential |
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what is relative refractory period |
when K+ channels stay open making it harder for a membrane potential to depolarize the cell |
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during AP the _ work all the time to transport back across the membrane the _ acts to maintain the ion concentration gradient |
Na+/K+ pump |
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what is a voltage gated sodium chanel |
a protein that forms a pore in the membrane that is highly selective to Na, pore opens and closes depending on the electrical potential of the membrane |
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why are Na+ channels 12x more permeable to Na+ than K+ |
they have pore loops that are assembled into a sleclectiveity filter |
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what effect does does chaning the potential from -80 to -65 have? |
no effect |
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what effect does changing the membrane potential from -65 to 40 mV have |
channels open with little delay h |
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how long to Na+ voltage gated ion channels stay open for |
1 MM |
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when can the Na+ channels reopen? |
only when the membrane is a at a negative state near threashold |
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when do voltage gated K+ channels open |
in response to depolarization (like Na+ channels) |
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what is the delayed rectifier |
the increase in K+ conductance tries to reset membrane potential during AP so K+ gates dont open right away (unlike Na+ channels) |
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what is orthodormic conductance |
current flowing inward at a point on the axon spreads out along the axon during AP depolarixing membrane |
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at the molecular level the Absolute refractory period corresponds to |
the time it takes activated Na+ channels to recover from inactivation |
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the absolute refractory period ensures that the AP... |
only moves in 1 direction |
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the typical neuron conducts at what speed? |
10 m per second |
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what does the speed of the AP depend on? |
axonal diameter and is the axon is wrapped in myelin |
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is myelin continuous |
no it breaks in "nodes of ranvier" |
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why are the nodes of ranvier important? |
voltagte gated channels are in the membrane of the nodes |
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what is saltatory conduction |
AP jumps from node to node in myelinated axons (making it a fast AP) |
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action potentials are only a feature of the |
axon |
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where is the spike initiation zone |
at the axon hillock |
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what is synaptic transmission |
echange of info btwn neurons |
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what are the kinds of synaptic transmissions |
chemical and electrical |
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what is a synapse |
a specialized junction where 1 neuron contacts and communicated with another |
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what is the difference btwn a chemical and electrical synapse
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gap junctions btwn pre and post synaptic membrane permits current flow passively though intercellular channels (elecrical) no direct flow of current from pre to post synaptic cell, NT secrete into cleft and bind to receptors |
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what allows current to pass through in elecrtical synapses |
6 connexins combine to make a connexon then 2 connexons connect to make a gap junction for the current to pass |
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is the synapse is large the electrical synaptic trasmission is.. |
fast and fail safe |
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most gap junctions are |
bidirectional (unlike chemical synapse |
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when 2 neurons are elecrically coupled, an AP in the _ causes a _ in the second neuron |
presynase causes post syn potential |
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in elecrticaltransmission, the membrane potential of the postsyn may cause change in the presyn, why? |
due to the bidirectional flow of ions |
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electrical synapses are often found when |
during embryonic stage, where normal functioning needs the acitivy of neighboring neurons to be highly syncronized |
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the presyn and postsyn membranse are seperated by a synaptic cleft in |
chemical synapses |
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what is the synaptic cleft filled with? |
a matrix of fibrous extracellular protein |
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which side is at the axon terminal and contains dozens of enclosed spheres called synaptic vesicles? |
the presynatpic side |
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what do synaptic vesicles store? |
NT |
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what are secretory glands |
large vesicles at the end of axon terminals that contain sloube protein |
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what are membrane differentiation |
dense accumlataions of protein adjacent to and within the mem on either side of the synaptic cleft |
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what are active zones |
the site of NT release |
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where can we find synaptic vesicles? |
in the cytoplasm of the synapse close to the active zone |
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what is post synaptic density |
proteins acculmalited under the post syn membrane |
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what does the post synaptic denisty contain |
the NT receptors that convert chemical signals into intracellular signal in the post synaptic cell |
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the post synaptic membrane is on the dendrite (CNS) |
axodentritic synapse |
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axosomatic synapse |
the postsyn membrane is on the cell body |
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axoaxonic |
the postsynaptic membranse is on another axon |
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asymmertrical synapse in which membrane differentiation on the postsyn is thinker than the presyn |
Gray's 1 type excits |
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synapses in which the membrane differentiations are similar in thickness |
grays 2 type inhibits |
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neuromuscualr junction |
chemical synapses that occur btwn the axon of a motor neuron of the spinal cord and skeletal muscle |
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what are the requirements for a chemical synaptic transmission |
-something to synthesize NT and pack them into vesicle -something to cause vesicle to release NT to cleft -something to produce an elecrtical or biochem response to NT in the post -something to remove NT from the cleft -something to execute all above |
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NT that mediates fast synaptic transmission at all neuromuscular junctions |
acetylcholine |
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chemical synaptic transmission requires NT to be |
synthesized and ready for release |
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NT _ and _ are among the 20 amino acids that are building blocks of protein |
glutamate and glycine |
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_ and _ are made only by the neurons that relase them |
gaba and amines |
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how do amino acids and amines get synthesized |
a synthesizing enzyme transports NT to the axon where they locally and rapidly direct transmitter synthesis |
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what happens once the NT is synthesized |
they are taken up by a synaptic vesicle |
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what concentrates the NT in the vesicle |
the transporter |
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how do peptide NT get synthesized |
the golgi slpits the peptide and the smaller fragment becomes the active NT |
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how do peptide NT get transported |
secretory granules that hold NT transport it to the axon terminal |
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how do nt release |
ap arrives at axon terminal, depolarization causes Ca+ channels to open in the active zone |
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when happens when Ca+ channels open |
ions come in bc of concentration gradient |
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the signal that triggers the relase of NT |
increase of calcium |
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process by which the synaptic vesicles fuse to the presynatpic mem at the active zone where the content of vesicles are released into cleft |
exocytosis |
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endocytosis |
recycled vesicles are filled with NT |
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how do secretory granules release peptide NT |
by exocytosis in a ca+ dependent manner but not at the active zones (takes longer) |
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what are the 2 types of receptors |
transmitter gated ion channels inotropic and g-protein coupled receptors metabotropic |
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structure of ion gated channels |
membrane spanninf protein consisting of 4-5 subunits that come together to form a pore |
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what happens when a NT binds to an ion gated receptor |
a conformational charge, a slight twist of the subunits causes the pore to open |
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excitatory postsynaptic potnetial (EPSP) |
a transient postsynaptic membrane depolarization caused by the release of an NT |
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important rule concerning transmitter gated ion channels |
if channels are permeable to Na+ the net effect will be to depolarize the post cell increasin chances of AP |
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example of what causes EPSP |
synaptic activation of gluatamate gated channels |
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what kind of net effect do tramister gated ion channels that are permeable to Cl+ have |
they hyperpolarize post syn cell |
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Inhibitory postsynaptic potential |
a transient hyperpolarization of the post synaptic membreane potential caused by the preseynaptic release of an inhibitory NT (gaba, gly) |
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g protein mediated receptors |
provide a fast chemical synaptic trasmission mediated by amine or AA NTs acting on NT gated ion channels |
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the 3 steps to NT action with G-protein coupled receptors |
NT binds to receptor, receptor activate gprotein that move along the intracellular face, activated G-protein active effector proteins(2nd msnger) that regulate ion channel function and alter cell metabolism |
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why is G-proetin known to be metabolic |
they can trigger metabolic effects |
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gprotein presynaptic receptors sensitive to the NT released by the pre synaptic terminal |
autoreceptors |
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autoreceptors inhibit |
NT release and synthesis |
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what allows presynaptic receptors to regulate itself and the level of NT in the synapse |
feedback from autoreceptors |
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how do NT leave the cleft |
neurottransporter proteins reuptake the NTm then they reload into vesicles or are destroyed in the cytoplsm |
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what role does the enzyme acetylocholinesterase have in the cleft |
it can sometimes destroy NT directly |
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the process by which multiple synaptic potentials combine within 1 post synap neuron |
synaptic intergration |
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larger EPSPs = |
more depolarizing increasing the chance that AP will fire |
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excitable dendrites have |
voltage gated channels |
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can ecitable dendrites generate AP? |
no but it can amplify it |
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many synapses w/ g-protein receptors that are not directly associated w/ an ion channel, they modify effectivness of EPSPs generated by other synaptses w/ transmitter gated channels is the process of |
modulation |
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amino acids and amines are generally release by |
seperate neurons |
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cotransmitters |
neurons that release AA or amine along with a peptide NT |
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cholingeic neurons release |
acetylcholin (Ach) |
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Acetylchoin is |
an NT @ the neuromuscular junctioon that contributes to the function of cicuits in the PNS and CNS |
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major neuron groups associated with acetylcholine |
medial spetum nucleus basalis laterodorsal and pedunculpontine tegmental nuclei complex |
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which enzyme synthesizes acetylcholine (Ach) |
choline acetytransferase |
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what are the 2 main classes of acetylcholine receptors |
nicotinic acetylcholine nAChR muscarinic acetylcholine mAChR |
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nAChR |
receptors stimulated by nitcotine and acetylcholine, premeable to Na+, K+ and Cl- (ionotropic) |
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mAChR |
metabotropic g-protein coupled receptors, affect neurons over a long time frame, stimulated by muscarine and acetylcholine and bloacked by atropine |
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which amino acid is the precursor for DA NE and epinepherine |
tyrosine |
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catecholaminergic neurons release |
DA NE and epinepherine |
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catecholamine neurons contain the enzyme _ that catalyzes the first step in the catecholamine synthesis the conversion of _ to _ |
tysosine hydroxylase, tyrosine, dopa |
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dopa is converted into dopamine by the enzyme |
dopa decarboxylase |
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what is dopamine's function |
motivation, behavior, cognition, motivation,movement, punishment,mood |
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the major neural pathways where dopaminergic neurons are found |
ventral tegmental area (prefrontal cortex and nucleus accumbus) and substantia nigra (striatum |
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dopamine receptors are a class of |
metabotropic g-protein receptors |
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what are the subtypes of DA receptors |
D1-D5 |
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what converts DA into NE |
the enzyme beta-hyroxylase |
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it can be a harmone or a NT that is found in the autonomic nervous system |
NE |
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what are the 2 main NE receptors |
a (Gprotein) and b (linked to gprotein) |
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_ NT is release when psysiological changes are activated by a stressful even caused by activation of the locus coeruleus |
NE |
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adrenergic neurons release |
epinepherine |
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what converts NE to epinepherin |
the enzyme phenylenthanolamine methyltransferase |
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where does NE convert to epinepherine |
in the cytosol |
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which amino acid is seretonin derived from |
tryptophan |
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what does seretonin play a role in |
mood, emotion, behvaiour and sleep |
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how is seretonin synthesized |
enzyme typtophan converts it |
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what happens when setonin is released |
romved by specific transporter back into the cytosol, degraded by MAO or goes back into synaptic vesicles |
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where are serotogenic neurons found |
in the raphe nucleus |
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serotonin receptors are |
g-protein coupled and ligan gated ion channels found in CNS and PNS |
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3 amino acid neurotransmitters that serv at most CNS synapses |
glu, glycine and gaba |
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most exitatory NT in the vertebrate Nervous system |
glutamate |
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glutamate receptors are |
ionotropic or metabotropic |
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glycine is an |
inhibitory NT, participates in motor and sensory information that permits movement, visio and audition |
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is gaba an alpha amino acid |
no |
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the chief inhibitory NT in the mammalian CNS that plays a role in regulation of neuronal excitability throughout the nervous system |
gaba |
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NT that is synthesized by glutamate using the enzyme L-glutamic acid decarboylase, this NT from glutamate to _ |
GABA |
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how are amino acid NT terminated |
selective reuptake into presynaptic terimal and glial |
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when gaba is terminated what happens |
its metabolized by enzyme gaba transaminase into succinic semialdehyde |
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gaba a receptors are part of |
ligand gated ion channel complex |
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gaba b receptors are |
metabotropic receptors |
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what is the endogenous endocannabinoid system essential for? |
physiological modulation of neural functions |
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a group of neuromodulatory lipids that are involved in appetite, pain sensation, mood and memory |
endocannabinoid |
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canabinoid receptors are |
CB1 and CB2 (gprotein coupled receptors) |
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what are the most abundant metabotropic receptors in the brain |
CB1 |
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what are the physiological ligands (stubstance) for the cannabinoid receptors |
AEA, 2-AG |
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are endocannabinoids stored in the cell? |
no they are synthesized and released on demand |
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how do endocannacinoids get release? |
the postsynaptic cell produces endocannabinoids that are released in retrogradeby facilied diffusion into the cleft |
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where to endocannabinoids bind |
to receptor sites found on the presynatpic side |
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what happens to endocannabinoids when they are done binding |
they get reuptaken by the pre and degradated by enzymes (fast metabolism) |
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WHAT HAPPENS when the CB1 receptors are activated |
it may inhibit the release of NT in the pre syn |
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fast synaptic chemical transmission acts on which channels |
transmitter gated ion channels |
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what happens when a NT binds to a transimmter gated ion channel |
the pore opens and lets ions in or out |
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the direct link between transmitter binding and opening or closing of the ion channel is a characteric of |
transmitter gated ion channels |
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the direct link between NT receptors and ion channels is contrasted with |
the indirect function of the g protein coupled recepors |
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what are the 3 steps involved in gprotein receptor transmission |
binding of NT to receptor activation of g proteins activation of effector systems |
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Gprotein receptors are made of |
a polypeptide containing 7 membrean spanning alpha helixices |
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which type of effector protein is the shortcut pathway |
the g protein gated ion channel |
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what is the second messanger cascased |
elaborate series of biochemical reactions that alter neural function |
