Synapses Flashcards by Simon Blum

Contains protein molecules that transmit chemical messages

Presynaptic membrane

How well did you know this?

Not at all

Perfectly

What NTs are commonly reuptaken by astrocytes and why?

Glutamate and GABA because they are very excitatory and inhibitory (respectively)

How well did you know this?

Not at all

Perfectly

Not typical at axon terminals. Synapses are not usually this type

Electrical synapse “gap junction”

How well did you know this?

Not at all

Perfectly

A method of NT deactivation that requires certain molecules to find and break down specific NTs

Breakdown by enzymes

How well did you know this?

Not at all

Perfectly

This postsynaptic receptor opens channels directly, provides immediate rxns required for muscle activity and sensory processing, has a fast activation, has a brief duration and is the classic model of ligand-gated receptors

Ionotropic receptors

How well did you know this?

Not at all

Perfectly

What method of NT inactivation did the first attempts to prevent depression use

Breakdown of enzymes. MAOs

How well did you know this?

Not at all

Perfectly

Type of synapse in which the axon terminal secretes directly into the bloodstream

Axosecretory

How well did you know this?

Not at all

Perfectly

What are the 4 ways of inactivating a NT?

Diffusion, breakdown by enzyme, uptake into glial cells, reuptake into presynaptic terminal via transporter

How well did you know this?

Not at all

Perfectly

NT is released toward a single postsynaptic neuron in this type of synapse

Directed synapse

How well did you know this?

Not at all

Perfectly

What is it called when a different neuron is involved with facilitation or inhibition of another neuron presynaptically? It is affecting another neurons decision

Neuromodulation

How well did you know this?

Not at all

Perfectly

Small space separating presynaptic terminal and postsynaptic dendritic spine

Synaptic cleft

How well did you know this?

Not at all

Perfectly

Type of synapse in which an axon terminal ends on soma

Axosomatic

How well did you know this?

Not at all

Perfectly

How can blocking and supercharging reuptake receptors have an effect on us?

They can have many different medical applications

How well did you know this?

Not at all

Perfectly

These are activated by a NT (first messenger)

g-proteins

How well did you know this?

Not at all

Perfectly

How are NTs stored

Vesicles which are membrane-bound organelles in the axon terminal

How well did you know this?

Not at all

Perfectly

Direct AP propagation, nearly instantaneous, only excitatory

Electrical synapse “gap junction”

How well did you know this?

Not at all

Perfectly

Site to which a NT molecule bonds

Postsynaptic receptor

How well did you know this?

Not at all

Perfectly

What are the six steps for triggered release of a NT

) Arrival of AP at axon terminal
) VG Ca channels open; calcium enters and SNARE proteins activate
) Vesicles move to and dock on presynaptic membrane
) Vesicles fuse with presynaptic membrane and release NT into synaptic cleft (exocytosis)
) NT binds with receptors on pre or postsynaptic membrane
) NT is inactivated or removed from synaptic cleft

How well did you know this?

Not at all

Perfectly

What are the two types of pre-synaptic receptors?

Heteroreceptors and autoreceptors

How well did you know this?

Not at all

Perfectly

When a vesicle fuses with the presynaptic membrane and releases NTs into the synaptic cleft

Exocytosis

How well did you know this?

Not at all

Perfectly

The gap is small at around 20 nm. The junction where neurotransmitters are releases

Chemical synapse

How well did you know this?

Not at all

Perfectly

Bi-directional. Message can travel both ways

Electrical synapse “gap junction”

How well did you know this?

Not at all

Perfectly

Typical at axon terminals. This is the most common synapse we see

Chemical synapse

How well did you know this?

Not at all

Perfectly

These postsynaptic receptors open channels indirectly, are versatile, use second messengers (g-proteins), have a slow activation, and have a long lasting duration of effects

Metabotropic receptors

The gap is very small at about 3.5 nm. The presynaptic and postsynaptic membrane are fused at the connexon. Shared cytoplasm

Electrical synapse "gap junction"

Type of synapse that is inhibitory, typically located on cell body, flat vesicles, sparse material on membranes, narrow cleft, and small active zone

Type II synapse

What are the four requirements to be a NT

Synthesis in cell, triggered release (AP), effect on receptors (a biological effect), and a mechanism for inactivation

Large compartment that holds synaptic vesicles

Storage granule

Organelle that provides the cell with energy

Mitochondrion

How is a NT synthesized in the axon terminal

Ingredients from food pumped into cell via transporters

A protein that acts as an assistant to bring the vesicles containing NTs to the presynaptic membrane to fuse

SNARE proteins

Type of synapse that is excitatory, typically located on dendrites, round vesicles, dense material on membranes, wide cleft, and a large active zone with lots of receptors on postsynaptic membrane

Type I synapse

The least common method of NT inactivation that occurs when the NT floats away from high concentration to low concentration

Diffusion

Proteins in membrane that respond to chemical messages; contain recognition molecules

Receptors

Round granule that contains NTs

Synaptic vesicle

Seen in areas like the heart to help it contract

Electrical synapse "gap junction"

What common treatment works by stopping the SNARE protein from pulling the vesicle to the presynaptic membrane and releasing NTs?

Botox

Presynaptic receptor that is involved with feedback, regulation, and reuptake. "Self"

Autoreceptors

A chemical that carries a message to initiate a biochemical process that isn't a NT

second messengers (g-proteins)

EPSPs, IPSPs, and initiation of other chemical rxns and biological processes are involved with these types of receptors

Postsynaptic receptors

How can we increase or decrease NTs?

Blocking/supercharging reuptake receptors, not allowing astrocytes to uptake NTs, increasing or decreasing certain amounts of enzymes, adding or taking away astrocytes to encourage diffusion or encourage uptake

The classic model of ligand-gated receptors

Ionotropic receptors

Excites or inhibits other neurons. Allows more signaling flexibility

Chemical synapse

A method of NT inactivation that occurs when presynaptic auto receptors take up the NT with a transport protein to be repackaged and used again

Reuptake

How is a NT synthesized in the cell body

DNA to RNA proteins, transported on microtubules to axon terminal, bigger molecules called neuropeptides are more likely to be formed here as opposed to axon terminal

When axoaxonic synapses between an axon terminal and another axon fiber have an effect on the release of neurotransmitters by the target axon through presynaptic facilitation or presynaptic inhibition

Neuromodulation

The released NT diffuse over a wide area to effect many neurons in this type of synapse. Has a bit of a bigger gap

Non-direct synapse (volume transmission)

Type of synapse in which the axon terminal end on a dendrite spine (the type we see most often)

Axodendritic

Type of synapse in which the axon terminal secretes into a another axon

Axoaxonic

Some receptors use two different messengers. What are they?

The first are NTs and the second are g-proteins (guanine)

A method of NT inactivation that occurs when an astrocyte takes a NT in, deactivates it, and sends it back into the postsynaptic terminal

Uptake into glial cells

What are the two types of postsynaptic receptors?

Ionotropic and metabotropic

What can g-proteins do?

alter rate of ion flow in a membrane channel, formation of new ion channels, production of new proteins through DNA

What are the 6 parts of a synapse?

Presynaptic membrane, synaptic cleft, postsynaptic membrane, mitochondrion, synaptic vesicles, and receptors

Axo-axonic presynaptic receptors involved with neuromodulation

Heteroreceptors

Type of synapse in which an axon with no connection secretes into extracellular fluid

Axoextracellular

Type of axon terminal in which an axon terminal ends on another axon terminal

Axosynaptic

Contains protein receptor molecules that receive chemical messages

Postsynaptic membrane