Chapter 8 - Glutamate Synthesis, Release, Innactivation

Glutamate

An amino acid found in all cells, an ionized form of AA

In all cells because all cells need experience excitation

Used in Glutamatergic Neurons

Glutamine

He precursor of Glutamate

Glutaminase

The enzyme that turns Glutamine into Glutamate

Asperate

An excitatory NT

Vesicular Glutamate Transporter (VGLUT 1-3)

The transporters of Glutamate

VGLUT 1

Found in the hippocampus and in the cortex

Knockout mice die after 3 weeks

VGLUT 2

Found in subcortical Areas

Without the transporter, mice die

VGLUT 3

Knockout mice survive, but are deaf

Glut with other NT

It is often expressed with other NT —> Released as cotransmitters with 5-HT, GABA, ACh, DA, ect

Can be released in the same vesicle, or can be segregated.

• DA is released with GLUT, but in separate vesicles in the VTA

Can be released at terminal at the same time, or segregated

Excitatory Amino Acid Transporters (EAATs)

Collects excess excitatory NT via Reuptake and transports them to be innactivated

5 different kinds, found mostly in Glial Cells (astrocytes)

EAAT1

Found in Astrocytes and in the Cerebellum

EAAT2

Found in Astrocytes

Knockout mice develop siezures and have short lifespans

EAAT3

Expressed in Purkinje cells in Cerebellum

EAAT5

Present in bipolar cells in the retina

Glutamine Synthatase

The enzyme that converts Glutamate into Glutamine

Knockout mice die at birth; humans have brain deformaties, short lifespans, and seizures (also too much NH3)