Neurophysiology L5

Question 1

Indirect Coupling (not metabotropic)

Answer 1

G-protein control an ion channel directly. Less modulated then metabotropic coupling
Indirect coupling can also refer to metabotropic

Question 2

Ligand -Gated Channel

Answer 2

Another name for ionotropic

Question 3

G - Protein Mechanism

Answer 3

• Inactive G protein has its alpha beta gamma subunits together and GDP bound
• Ligand binds receptor and G protein associated
• The GDP is replaced with GTP thus breaking the alpha from the Beta Gamma
• Subunits go off to cause other results
• once hydrolyzed back to GDP the G protein comes back together

Question 4

G-Protein – Gs

Answer 4

Activated Adenyl Cyclase (AC)

goes to activate cAMP which can act on an ion channel or go to activate a protein kinase

Question 5

Phosphodiesterase (PDE)

Answer 5

Breaks down cAMP thus showing a way of modulation. It will stop the path
Caffeine inhibits PDE so cAMP goes up

Question 6

G-Protein – Gc

Answer 6

Activated Guanylate cyclase (GC) to make cGMP

Gi is an example of this in the eye

Question 7

G-Protein – Gi

Answer 7

Inhibits AC thus decreasing cAMP and modulation of ion channels

Question 8

G-Protein – Gq

Answer 8

Activated Phospholipase C (PLC) thus cleaving diacylglycerol to DAG and IP3
IP3 goes to release calcium from ER
Calcium with DAG go to activate protein kinase C

Question 9

G-protein – Golf

Answer 9

Activated by odors increases cAMP directly increasing sodium and calcium permeability. leading to depolarization. Golf is a specific Gs

Question 10

G-protein – Geye (in the eye)

Answer 10

G-protein in retina called transducin activated by rhodopsin. activates a PDE hydrolyzing cGMP closing Na and hyper polarizing

Question 11

NT - Dopamine (classification, type of receptor used)

Answer 11

Biogenic Amine, Several receptors all G-protein Coupled

Question 12

Result of Low Dopamine

Answer 12

Parkinsons - relieved with DOPA

Question 13

Result of High Dopamine

Answer 13

Leads to schizophrenia. so use receptors to block

Question 14

Effect of Cocaine and Amphetamines

Answer 14

Block re-uptake of Dopamine so remains in cleft. dopamine leads to pleasure

Question 15

Serotonin (classification and receptor)

Answer 15

Many receptors is a biogenic Amine.

Question 16

Lack of Serotonin Results

Answer 16

Leads to depression. Treat with SSRI. it inhibits serotonin reuptake

Question 17

MDMA/ LSD

Answer 17

agonist of serotonin by activating receptor. Causes euphoria.

Question 18

Production of Serotonin

Answer 18

Produced from tryptophan and oxidized by MAO

Question 19

Histamine (classification and receptors)

Answer 19

Produced by decarboxylation of histidine 3 receptors. involved in allergic reactions. Biogenic amine

Question 20

Glutamate As a NT (where seen and receptors)

Answer 20

seen in many excitatory
seen in brain for memory
Amino acid has 3 ionotropic receptors
- Kainate, AMPA and NMDA

Question 21

NMDA and AMPA process

Answer 21

NMDA - both ligand and voltage gated
What happens
- pore is blocked by Mg2+ until depol to -60
- glutamate comes in binds AMPA and not until multiple stimulations on the AMP Adoes it Depol and reach causing NMDA to open and creating a more slowly sustained response

Question 22

GABA (Receptors and Category)

Answer 22

Amino Acid category . Major inhibitory in brain. formed by glutamate.
GABAa and GABAb
GABAa - ionotropic increases permeability to Cl opposing depolarization
GABAb- Metabotropic through Gi protein that decrease permeability to Ca and Increases to K

Question 23

Barbiturates and benzodiazepins

Answer 23

they perpetuate inhibition by opening gCl opposing depolarization

Question 24

Glycine as a NT

Answer 24

Acts by Increasing gCl and is inhibitory and seen in spinal cord

Question 25

Substance P

Answer 25

Pain stuff excess can cause depression

Question 26

Opioid Peptides (receptors and category)

Answer 26

Neuroactive peptides
seen in feeling of euphoria
Acts on Kappa Nu and Delta Receptors
- which act on G proteins they will suppress pain by inhibiting VGCaC and increase K conductance

Question 27

NO (Nitric Oxide) (what it does, and how to potentiate)

Answer 27

Causes Vasodilation.
Activated Guanylate cyclase —> to a protein kinase
lifetime is short but could possibly be used to communicate post synaptic to presynaptic
To potentiate use a blocking of PDE like viagra

Question 28

Purines - ATP And Adenosine

Answer 28

act on G-protein or ligand gated channel. Adenosine is a CNS depressant