Animal Model 3 Flashcards
What other disorders is OCD co-morbid with?
Tourette’s, depression, schizophrenia
What are the most common obsessions?
doubts, indecisions, contamination, need for symmetry
What are the most common compulsions?
checking, washing, counting, hoarding
What is OCD?
inability in achieving a sense of task completion
What is the name of the circuit involved in OCD?
Alexander Circuit
Which areas of the brain show increased activity in OCD?
- orbitofrontal cortex
- basal ganglia
- thalamus
(direct pathway)
Which drug is used to induce OCD? Class?
quinpirole (dopamine D2/D3/D4 agonist)
What type of rat was used in the quinpirole model?
long evans rats
What were the main findings of the quinpirole model?
- 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
Does the quinpirole model fit the mckinney criteria?
- 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
repeated exposure to the startle stimulus results in ___________.
habituation or less response
What is prepulse inhibition (PPI)?
mild stimulus given before startle stimulus will decrease the startle response
Patients with schizophrenia show ___________ PPI. (excess/deficient)
deficient
Which drug disrupts PPI? Class of drug?
apomorphine (non-selective DA agonist)
Which drug type can reverse disrupted PPI?
antipsychotics
What can a stroke be caused by?
middle cerebral artery occlusion (MCAO) –> restrict blood flow –> apoptosis
What kind of drugs were developed in the stroke animal models to treat stroke?
- NMDA antagonists
- Edaravone, free radical scavengers
What is multiple sclerosis (MS)?
- CNS directed autoimmune disease
- T cell mediated inflammation, demyelination, axonal injury
What was the animal model for MS? Describe what occurred in this model.
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
What makes the Cre-Lox system different from other gene manipulation procedures?
knock-out/in a specific gene IN A DEFINED POPULATION OF CELLS
How do you use the Cre-Lox system?
1) flank gene of interest by adding loxP sites on either side
2) Cre recombinase cuts loxP sites
What are the advantages of the Cre-Lox system?
- no off-target effects
- turn on/off your gene manipulation at selected time point
What is optogenetics? How does it work?
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
Which channel is activated by blue light? Is it excitatory or inhibitory?
channel rhodopsin (ChR2); excitatory
Which channel is activated by yellow light? If it excitatory or inhibitory?
Halorhodopsin (NpHR); inhibitory
