Acetylcholine, Glutamate, and GABA

Question 1

Cholinergic system : synthesis to inactivation

Answer 1

synthesis

ChAT is the rate-limiting enzyme for the synthesis of acetylcholine

storage and release

acetylcholine’s storage inside the vesicles is mediated by the vesicular VAChT

inactivation

ACh is broken down by the enzyme ACeE into choline and acetate

Question 2

Cholinergic innervation within the CNS: Nucleus basalis

Answer 2

project to :

all segments of the cortex

Function:

learning and memory
loss of the cells is a characteristic of Alzheimer’s disease

Question 3

Cholinergic innervation within the CNS: Point mesencephalic

Answer 3

projects to :

reticular formation
Cerebellum
Thalamus

Function:

arousal and sleep-wake cycle

Question 4

Nicotinic receptors

Answer 4

respond to the agents nicotine, an alkaloid found in the tobacco plant

ionotropic receptors -excitatory

Question 5

muscarinic receptors

Answer 5

respond to muscarine, an alkaloid first isolated from the fly agaric mushrooms

5 subtypes : M1-M5

M1 most abundant in CNS
M5-only muscarinic receptor expressed in dopamine cells

Question 6

3 common types of nicotine ACh receptors

Answer 6

muscle nicotinic receptor

neuronal 4B2 receptor

neuronal x7 receptor

Question 7

ACh in the PNS

Answer 7

In the PNS, ACh mainly works at the neuromuscular junction of both skeletal muscles and the visceral motor system.

Question 8

VGLUT1(vesicular glutamate transporter )

Answer 8

found mostly in neurons of the neocortex and cerebellum

Question 9

VGLUT 2

Answer 9

found broadly across the cortex and subcortical areas

Question 10

VGLUT 3

Answer 10

found more often in the posterior midbrain and hindbrain areas

Question 11

Blank has a higher affinity for glutamate than BLANK, and can be activated by a lower concentration of the transmitter

one NMDA-R molecule required BLANK to be activated

Answer 11

NMDA-R

AMPA-R

2 glutamate molecules

Question 12

BLANK are composed by 4 subunits

Answer 12

Glutamatergic receptors

Question 13

Esketamine

Answer 13

1- block NMDR in GABAergic neurons

2- increase extracellular glutamate and activation of AMPA receptors

3- mTOR is activated and stimulates brain-derived neurotropic factor production

Question 14

General characteristics of GABAergic neurons

Answer 14

1.) Short axons-interneurons

2.) Form synapses mostly in the soma of the postsynaptic cell

3.) Fire Action Potentials at relatively high firing frequencies

4.) Very often have small “somas”

Question 15

What is the rate-limiting for the synthesis of ACh?

Answer 15

ChAT