Animal Model 3

Question 1

What other disorders is OCD co-morbid with?

Answer 1

Tourette’s, depression, schizophrenia

Question 2

What are the most common obsessions?

Answer 2

doubts, indecisions, contamination, need for symmetry

Question 3

What are the most common compulsions?

Answer 3

checking, washing, counting, hoarding

Question 4

What is OCD?

Answer 4

inability in achieving a sense of task completion

Question 5

What is the name of the circuit involved in OCD?

Answer 5

Alexander Circuit

Question 6

Which areas of the brain show increased activity in OCD?

Answer 6

• orbitofrontal cortex
• basal ganglia
• thalamus
  (direct pathway)

Question 7

Which drug is used to induce OCD? Class?

Answer 7

quinpirole (dopamine D2/D3/D4 agonist)

Question 8

What type of rat was used in the quinpirole model?

Answer 8

long evans rats

Question 9

What were the main findings of the quinpirole model?

Answer 9

• increased frequency of visit to home base
• increased rate of visit to home base
• faster return time to home base
• less visits to other zones on trips
• rituals at home base

Question 10

Does the quinpirole model fit the mckinney criteria?

Answer 10

• similarity of inducing conditions: QNP = D2 agonist –> DA imbalance in humans ass. with social/emotional circumstances?
• similarity of behavioural state induced: compulsive checking and rituals present –> YES
• similarity of clinically effective treatments: clomipramine works –> YES

Question 11

repeated exposure to the startle stimulus results in ___________.

Answer 11

habituation or less response

Question 12

What is prepulse inhibition (PPI)?

Answer 12

mild stimulus given before startle stimulus will decrease the startle response

Question 13

Patients with schizophrenia show ___________ PPI. (excess/deficient)

Answer 13

deficient

Question 14

Which drug disrupts PPI? Class of drug?

Answer 14

apomorphine (non-selective DA agonist)

Question 15

Which drug type can reverse disrupted PPI?

Answer 15

antipsychotics

Question 16

What can a stroke be caused by?

Answer 16

middle cerebral artery occlusion (MCAO) –> restrict blood flow –> apoptosis

Question 17

What kind of drugs were developed in the stroke animal models to treat stroke?

Answer 17

• NMDA antagonists
• Edaravone, free radical scavengers

Question 18

What is multiple sclerosis (MS)?

Answer 18

• CNS directed autoimmune disease
• T cell mediated inflammation, demyelination, axonal injury

Question 19

What was the animal model for MS? Describe what occurred in this model.

Answer 19

experimental autoimmune encephalomyelitis (EAE)

• immunize rodent with specific myelin peptide (antigen)
• immune system mounts a response against the myelin antigen (found in brain and spinal cord)
• weakness/paralysis scored

Question 20

What makes the Cre-Lox system different from other gene manipulation procedures?

Answer 20

knock-out/in a specific gene IN A DEFINED POPULATION OF CELLS

Question 21

How do you use the Cre-Lox system?

Answer 21

1) flank gene of interest by adding loxP sites on either side
2) Cre recombinase cuts loxP sites

Question 22

What are the advantages of the Cre-Lox system?

Answer 22

• no off-target effects
• turn on/off your gene manipulation at selected time point

Question 23

What is optogenetics? How does it work?

Answer 23

optogenetics: controlling neuronal activity with light

1) ion channel protein (from algae) only opens in response to BLUE light
2) insert protein’s DNA into specific neurons in brain
3) shining BLUE light on those neurons causes firing

Question 24

Which channel is activated by blue light? Is it excitatory or inhibitory?

Answer 24

channel rhodopsin (ChR2); excitatory

Question 25

Which channel is activated by yellow light? If it excitatory or inhibitory?

Answer 25

Halorhodopsin (NpHR); inhibitory