Part 3: Synthesis, release, & inactivation of Glu and GABA

Functions of glutamine and what is it derived from

Glutamate is a primary excitatory NT

• has many other metabolic roles

• derived from glucose and glutamine (With ATP)

What are VGLUTs

Vesicular glutamate transporters that move glutamate into vesicles

What is a main classification that makes glutamate a NT?

Must be from a glutamatergic neuron

*glutamate can be expressed as a co-transmitter

What is VLUT 2 in charge of

Breathing

What is VLGUT 3 function

Deaf with no inner hair of the cochlea

How is glutamate inactivated

It is immediately removed by glutamate transporters from the synaptic cleft (EAAT 1-5)

These transports also take up asparate

What happens if glutamate is inactivated?

Can increase seizure risk

What do astrocytes transports after uptake do?

Turn glutamate into glutamine to be turned back into glutamate and released further

5 steps of glutamate synthesis through inactivation

1. Glutamine is synthesized to glutamate by glutaminase

2. Glutamate is moved into vesicles by VGLUT

3. EAAT reuptake

4. Astrocytes transforms glutamate to glutamine

5. Glutamine is safely transported so no extra glutamate causes unnecessary excitatory effects

How is GABA synthesized and by what neurons and what is it main function as a NT?

Major inhibitory NT

Synthesized by glutamate only by GABAergic neurons containing GAD (glutamic acid_

What happens when GAD is blocked

Leads to seizures and death

What transporter aids release of GABA

VGAT (vesicular GABA transporter) moves GABA into vesicles for release

• they also transport glycine

How is GABA inactivated?

Removed by GAT 1,2,3

In astrocytes, glutamate is converted to glutamine which can be released by astrocytes