Chemical Messengers

Question 1

Where are neurons that make ACh? (2)

Answer 1

Brainstem.

Striatum of basal ganglia.

Question 2

Function of ACh from the striatum?

Answer 2

Control of voluntary motion

Question 3

Function of ACh from the brainstem?

Answer 3

Baseline excitation to cortex.

REM sleep.

Question 4

ACh is synthesized from:

What transporter move ACh into a vesicle?

What removes ACh from synapse?

Answer 4

Choline and acetate.

VAChT.

AChE

Question 5

Muscarinic receptors of ACh
M1
M4
M5

Answer 5

M1: neuronal. Gq.
M4: presynaptic autoreceptor; striatum of basal ganglia. Gi.
M5: cerebrovasculature; basal ganglia. Gq.

Question 6

Location of nAChRs in the body (3)

Answer 6

NMJ
ANS
CNS

Question 7

How can nAChRs allow Ca++ in?

Answer 7

There are 5 subunits and 16 genes. They can change their properties to allow Ca++.

Question 8

Inhibitory AAs

Answer 8

GABA

Glycine

Question 9

Where is GABA found?

Answer 9

Most in superior CNS. Decreases as you move inferiorly (SC has least).

Major inhibitory AA in CNS.

Question 10

3 critical roles of GABA

Answer 10

Consciousness
Motor control
Vision (retina)

Question 11

What is GABA synthesized from?
What enzyme is important in its synthesis?
How does it get into vesicles?
How is it removed from synapse?

Answer 11

Glutamate
GAD (glutamate decarb)
VGAT
GAT1, GAT2

Question 12

GAT1 vs GAT2

Answer 12

GAT1 is on presynaptic terminals and reuptakes GABA.

GAT2 is on glia/astrocytes nearby that turn it into glutamine and that re-enters the presynaptic terminal.

Question 13

GABA A receptor:

Modulators:

Answer 13

Ionotropic.
Increases Cl- –> IPSP

Modulated by Benzos, EtOH.

Question 14

How can GABA receptors be used as a target for anesthetics?

Answer 14

GABA A exists on many extra-synaptic places, and therefore it is targeted.

Question 15

GABA B receptor:

How does its location on the presynaptic or postsynaptic terminal effect its function?

Answer 15

Metabotropic.
Gi/Go pathways (+ K+ channels, - Ca++ channels).

Presynaptic: regulate NT release.
Postsynaptic: inhibits post-synaptic cell.

Question 16

Location of Glycine:

Function:

Produced from:

How is it removed from synapse?

Answer 16

Most in SC, and decreased as you move superiorly.

Mediates spinal inhibitions.

Glycine

GAT proteins, or recycled

Question 17

What is the receptor for Glycine?

What does it lead to?

What can potentiate it?

Answer 17

Ionotropic.

Influx of Cl- –> IPSP at SC.

EtOH and anesthetics potentiate it.

Question 18

Stychnine function

Answer 18

Blocks the glycine receptor and can lead to convulsions

Question 19

What protein allows for uptake of ATP?

Answer 19

VNUT

Question 20

P1 receptors and ligand:

Postsynaptic vs presynaptic functions:

Answer 20

Receptors for adenosine on post-synaptic terminals.
Postsynaptic functions: Induce sleep and inhibit general neuronal functions.
Presynaptic functions: inhibit NT release.

Question 21

P2X receptors and ligand:

Type of receptor:

Answer 21

ATP.

Ionotropic.

Question 22

P2Y receptors and ligand:

Type of receptor:

Answer 22

ATP, ADP, UTP, UDP.

Metabotropic (Gi/Gq coupled)

Question 23

Functions of the P2 receptors (3)

Answer 23

Learning
Memory
Modification of locomotor pathways

Question 24

Locations of where opiods act (3)

Answer 24

Basal ganglia
Hypothalamus
Brainstem

Question 25

General functions of opiods

Answer 25

Modify pain sensation | Effect mood/personality

Question 26

Precursor molecules for: Endorphins: Enkephalins: Dynorphins: Nociceptins:

Answer 26

Endorphins: PCOM Enkephalins: pro-enkephalins Dynorphins: pro-dynorphins Nociceptins: orphanin

Question 27

How are opiods removed from synapse?

Answer 27

Reuptake are enzymatic destruction

Question 28

u (mu) receptor type and its effects

Answer 28

Metabotropic: increase in K+ efflux --> hyperpolarization ``` Analgesia Respi depression Euphoria Constipation Sedation ```

Question 29

Kappa receptor type and effects

Answer 29

Metabotropic: decrease Ca++ influx Analgesia Dysphoria (depression)

Question 30

Delta receptor type and effects

Answer 30

Metabotropic: decrease Ca++ influx Analgesia

Question 31

2 identified endogenous cannabinoids

Answer 31

Anandamine | 2-AG

Question 32

Where are the 3 big locations of cannabinoids in the body and what does it effect? Where else is it located?

Answer 32

Basal ganglia: mood, motor control. SC: modulation of pain. Cortex: neuroprotection. Hippocampus and hypothalamus

Question 33

Synthesis of cannabinoids (2)

Answer 33

Derived from membrane lipids (arachidonic acid) and occurs in presynaptic terminal.

Question 34

CB1 receptor is found where? | What does it do there? Via which receptor pathway?

Answer 34

Found on presynaptic terminal of EAA and GABA releasing synapses. Inhibits EAA and GABA release via Gi.

Question 35

CB2 receptor is associated with what? What does it do? What disease is it associated with?

Answer 35

Immune system (microglia, gut, etc). Anti-inflammatory effects. May help remove beta-amyloid plaques in patients with AD.