Pharmacology & the CNS

Question 1

ILO1

State the ways in which a drug can act in the CNS (i.e on the receptor themselves

Answer 1

Agonist - Activates receptor, produces functional response in cell

Antagonist - inhibits receptor by bindng to it, blocks agonist binding

Partial Agonist - partially activates a receptor, producing lesser functional response

Question 2

ILO1- Moa of CNS drugs

State ways in which a drug can affect enzymes and ion channels in the CNS

Answer 2

Enzymes: Can inhibit their action. Could argue some drugs may indirectly potentiate an enzyme as well, via agonistic mechanisms.

Ion channels: Can open ion channels, allowing more ions through the target channel, can also act as a blocker, reducing the ion flow. Most drugs block ion flow.

Question 3

What chemical property is important for allowing drugs to reach the CNS

Answer 3

Lipophillic

Question 4

State routes of drug delivery to the CNS, and explain what they are

Answer 4

• Enteral (i.e by GI), lipophylic drugs
• Parenternal (administered or occurring elsewhere in the body than the mouth and alimentary canal.)
• Intrathecal (injection in the subarachnoid space)

Question 5

State examples of paraenternal routes of drug administration for the CNS

Answer 5

Intravenous

Intramuscular

Question 6

Give examples of classes of drugs tha that can be given intrathecally

Answer 6

• Antibiotics (meningitis)
• Chemotherapy
• Anti-spasmodics

Question 7

What structure severly restricts the subsatnces that can cross into the brain

Answer 7

BBB

Question 8

State functions of the BBB

Answer 8

• Prevent brain from foreign substances
• Prevent peripheral neurotransmitters entering the brain
• Maintain a constant biochemical and immunological environment for brain structures

Question 9

State the key components for the BBB

Answer 9

Endotliel cells

Basement membrane

Astrocyte end foots

Pericytes

Question 10

What structure holds the endothelial cells of the BBB together

Answer 10

Tight junctions

Question 11

State diseases/conditions that can damage the BBB, and the conseqeunces of this

Answer 11

• Hypertension
• Infection
• Trauma
• Dangerous substances can enter the brain via a damaged BBB

Question 12

What glucose transporter transports glcose across the BBB?

Answer 12

Glut-1

Question 13

Certain patients have mutations in Glut1 where they cannot transport glucose across the BBB. How do levels of glucose differ between the CSF and blood? Non-pharmacological treatment for this?

Answer 13

Glucose is high in blood, low in CSF.

Ketogenic diet

Question 14

State examples of neurotransmitters

Answer 14

GABA

Glutamate

Acetylcholine

Adrenaline

noradrenaline

Serotonin

Dopamine

Question 15

MIND MAP FOR NEUROTRANSMITTERS