synaptic transmission

clatherin

The membrane is removed by the use of ____ coted endocytosuis

synaptic cleft

The narrow gap that separates the presynaptic neuron from the postsynaptic cell.

Synapsin

The protein located on the outside of neurotransmitter vesicles in synaptic knobs which, when activated, causes them to fuse with the cell membrane and undergo exocytosis is:

executive and binding proteins

These are proteins involved in the SNARE complex to allow fusion

electrical synapses

(A) at ____ synapses, gap junctions occur between ore and post synaptic membrane. gap junction contain the channels passive current flow

chemical synapses

(C) at ____ synapses, there is no intracellular continuity, and no direct flow of current from pre to post synaptic cell. synaptic current flows across the membrane only in response to the secretion of neurotransmitters which open or close postsynaptic ion channels after binding to receptors

co-localization of neurotransmitters

-2 or more NTS within the same neuron -often neuropeptide co-localized with a small molecule NT

GTP

At the active zone, RAB is bound to ____ which does not allow the vessicle to dock

EPSPs

Excitatory postsynaptic potentials generated by depolarization , mostly mediated by glutamate (or aspartate) acting on AMPA or kainate receptors, occur in channels in which both Na+ and K+ can diffuse.

MEPPS

Fatt and Katz experiment: even when motor neurons were not stimulated, there were small changes in _____

Type I and Type II

In the central nervous system, there are two types of synapses.

recycling of the membrane

This occurs after fusion has occurred. Because the membrane gets bigger because of the vesicles plasma membrane fusion with the postsynaptic membrane.

readily releasable pool

Vesicles ready to be released are found in a region near the presynaptic terminal membrane called the ___

neurotransmitters

___ are synthesized by neurons. some are produced as byproduct of metabolism.

hydrolysis

_____of GTP is needed to break apart this complex which will allow the vesicle protein to interact with the docking complex

axon, neurotransmitters

action potential comes down to the end of the _____. stimulates the release of ______. this causes exocytosis and neurotransmitters are dumbed into the cleft and diffuse across the synaptic cleft. They bind to receptors on postsynaptic cell to activate it the neurotransmitters are removed from the synapse to prevent over stimulation

exocytosis

action potential in the terminus is a stimulus. opens voltage sensitive Ca channels opens with depolarization remains open as long as depolarization lasts. increase in Ca causes _____ of neurotransmitters into the synaptic cleft

axon terminus, transport proteins

amino acids and amines are synthesized in the _____. taken up into synaptic vesicle by way of _______ ______ because the they are charged and unable to diffuse through the bilayer

depolarization

amount of Neurotransmitters released increases as the membrane _____ increases. so action potential will cause release of a fixed amount of chemicals, but cells that don't create action potentials can also release NTs

protein mediated fusion pore

another mechanism of how vesciles are released

MEPPS

are about .5mV and occur randomly in the absence of no stimulus. This will occur when one vesicle released neurotransmitters.

presynaptic to postsynaptic

at electrical synapses, current flows directly from the _____ to the ___ cell.

dendrodendritic synapse

dendrite to dendrite. frequently reciprocal synapses. dendrites of one neuron can make synapses with dendrite on another neuron

Ca+

depolarization of the presynaptic terminal causes a increase in ___ permeability. The voltage gated Ca+ channel will open and cause calcium to flow down its concentration gradient from the outside to the inside of the synaptic terminal. Ca will interact with proteins associated with synaptic vesicles leads to the release of the chemical transmitter substance.

speeds

different transmitters are released with different ___. allows cells with co-localized transmitters to release them differentially based on cellular activity

motor end plate

generalized structure of chemical synapse. shows all structures. easy to get to as compared to chemical synapses within the CNS used as model chemical synapse

SNAP

helps to bind synaptobrevin to syntaxins to make the vesicles get closer and bind

remains

in chemical synapses, the current in the presynaptic cell ___ there. to get response in the postsynaptic, we must generate a new current

phosphorylated

influx of Ca+ ions activate kinases. synapsins release the vesicles when they are _____. vesicles are moved to the plasma membrane

synaptic cleft

mechanism of chemical transmission: it all relies on neurotransmitters they are relapsed by exocytosis from the presynaptic cell they diffuse across the ____ chemicals bind to receptors on postsynaptic cells. chemicals are removed from synapse. membrane is recycled

high frequency stimulation

more Ca coming in diffuses to the back part of the synaptic terminal. now we have neuropeptides released which can be released anywhere on the presynaptic membrane, doesn't have to be the bottom

chemical an chemical synapses

more common, found between neurons as well as between neurons and non neuronal cells. indirect current flow between cells. more adaptable/controllable

enzymes

neurons contain specific ____, used as a way of identifying subcategories of neurons.

Ca

neurotransmitter release is directly dependent on membrane depolarization. Not Sodium or potassium ion movement. It is dependent on ____ influx

SNARE complex

once the vesicle is able to bind, the _____ is created which is responsible for bringing the vesicle membrane closer to the plasma membrane

membrane

once vesicles are phosphorylates, they move to the active zone of the post-synaptic _____

soma, axonal

peptides are synthesized in the ___ in the ER. packaged into secretory vesicles in the Golgi. They are moved by _____ transport to axon terminus

synapse

point of transmission

junctional folds, postsynaptic densities, receptors

postsynaptic membrane structures

syntaxins

receptor protein found in the plasma membrane

type II synapses

smaller cleft, smaller active zones, decreased presynaptic densities, flattened or oval vesicles, little basement membrane

somasomatic synapse

soma of two neurons come together to make synapses. may see reciprocal synapses

synaptic knob

some vesicles are attached to sides of active zones. others are within the cytoplasm. Ca+ channels in close proximity to active zones

active zone, membrane, fusion pore

steps of exocytosis: 1. vesicles are restrained in pre-synaptic terminal 2. movement of vesicle to the _____ 3. docking of vesicles with protein on surface of vessicle with the _____ 4. priming 5. formation of _____ 6. release of neurotransmitters in postsynaptic vesicle 7. recycling of vessicle

axodendritic synapse

synapses between the axon endings of one neuron and the dendrites of other neurons. most common. most excitatory, some inhibitory. (a) in the picture

low frequency stimulation

synaptic vesicles are located near the presynaptic membrane. only these are exposed to Ca hence going under exocytosis.

function of electrical synapse

synchronization of the electrical activity of large populations of neurons. Hypothalamus, thalamus, neuronal development.

amplitude

the EPSPS are multiples of the unit synaptic potentials and the ____ depends on the number of vesicles released

gap junctions

the electrical synapses use ____, which are They directly connect the cytoplasm of two cells, which allows various molecules, ions and electrical impulses to directly pass through a regulated gate between cells.

phosphorylated

the influx of Ca+ ions will activate these kinases and cause the synapsis to be ______. This will cause the vesicles to be released from the actin

depolarization, Ca, into

the reason we get exocytosis of neurotransmitters in presynaptic cells, is because _______ opens voltage gated ___ channels causing Ca to come ___ the cell. Depolarization determines how long the channels are open for.

fusion pore

the release of neurotransmitters is a result of a _____.

lipid lined fusion pore

theory both membranes curve toward each other to form the early fusion pore. When the two membranes are brought to a "critical" distance, the lipid head-groups from one membrane insert into the other, creating the basis for the fusion pore.

Exocytosis

there are synaptic vesicles that release neurotransmitters that go through _____. from the pre-synaptic membrane they bind with the postsynaptic membrane to release neurotransmitters into postsynaptic to create a response

junctional folds

these are important because it increase the surface areas for where our receptors (neurotransmitters) are located

chaperones and synucleins

these work to prevent nonspecific interaction and misfolding's. They both support the formation of functional SNARE complexes by binding to SNAP or synaptobrevin

synaptotagamin

this binds to Ca+ which will allow for the fusion and is found in the vesicle membrane

glial and astrocytes

to clear neurotransmitters, we can use ____ and ____ to reuptake the neurotransmitters

enzymatic degradation

to remove neurotransmitters, you can use ____ which will use enzymes to chemically break them down

quanta

transmitter is released in small units called ____. one of these is one synaptic vessicle, which is about 5000 molecules of ACh

asymmetrical, excitatory

type I synapses are ___ in structure and _____ in nature

symmetrical, inhibitory

type II synapses are _____ in structure and _____

amino acids, amines, peptides

types of neurotransmitters

cAMP and Ca dependent kinases

types of synapsins

synapsins

vesicles are bound to actin by _____ proteins

synapsins

vesicles are bound to the pre-synaptic vesicle to actin by _______ proteins

exocytosis, capacitance

we have to undergo ____ because we add membrane to the button. we have to do this so the membrane does not get too big. and it changes electrical properties because it increases _____ and effects the function of the synapse

frequent

when depolarization of presynaptic cell occurred, the MEPPS became more _____, and they could block it with antagonists to abolish all spontaneous activity

desensitization

you must clear transmitters from cleft to prevent overstimulation of synaptic cells and _____

postsynaptic cell

cell which will receive information

presynaptic cell

cells which will convey information

axodendritic, axosomatic, axoaxonic

3 types of synapses and locations

active zone, fusion pore

1.restrain vesicles in (pre-synaptic) axon terminus 2.movement of vesicle to _____ where they will then fuse and cause release of NT upon influx of Ca 3.docking of vesicle (protein on surface and intracellular membrane) 4. priming 5. Formation of _____. vesicle and membrane proteins and release of Nts 6. recycling of vessicle via use of clathrin

Synaptotagmin

Ca+ might increase the pore size through the action of _____

Type I synapse

Large cleft, large active zone, dense projections from active zones, round vesicles, large postsynaptic density and basement membrane

MEPPs

Miniature end plate potentials

Ca2+

SNARE proteins bring the membranes together and ___ changes synaptoamin resulting in membrane fusion

axoaxonic synapse

axon terminal ends on another axon (C) picture

axosomatic synapse

axon to soma. primarily inhibitory

active zones

intracellular dense material adjacent to plasma membrane

synaptic bouton

is a structure in the presynaptic part that includes the synaptic vesicles, secretory vesicles, and active zones

EPPs

is due to the summation effects of many vesicles being released at the same time. One vesicle produces a potential of about 0.5 mV. The release of 200 of those vesicles at the same time could produce a potential which is 100 times as great (40 mV). so its due to many MEPPS

vesicles

less calcium means there will be less _____ released and therefore less neurotransmitters released. •levels of intracellular calcium ions in presynaptic cell determines how many vesicles undergo exocytosis at any given time

electrical synapse

less common, found predominantly in CNS, slow direct current spread from presynaptic to postsynaptic cell. allow for coordination of activity

synaptic transmission

mechanism by which neurons transfer information to other cells (communication with other neurons, muscle cells, glandular cells)