1. Christine Yen [鄧思婷]
Taiwan Tech Trek Academic Conference August 14, 2015
Modeling Neurodegenerative
Diseases in Mice
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2. Parkinson’s Disease (PD)
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• Characteristics
- Loss dopaminergic neurons in
substantia nigra pars compacta
(SNpc)
• Causes: unknown, sporadic
- Genetic, environmental factors
• Prevalence
- Primarily among elderly
- 1-3% of population over 55 yrs
http://what-when-how.com/wp-content/uploads/2012/04/tmp3675_thumb_thumb.jpg

3. Parkinson’s Disease
• Pathophysiology
-SNpc releases dopamine-> receptors
in striatum
- Dopamine deficiency
- Striatum cannot signal
motor thalamus, basal ganglia
• Symptoms
- Tremors, rigidity, bradykinesia
difficulty walking
- Dementia
http://file.scirp.org/Html/2-2620020/24f49151-d68f-4540-bd71-c1b45e35562d.jpg
http://discovermagazine.com/~/media/Images/Issues/2014/March/dopamine-chart.jpg
Striatum
SNpc
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4. 6-OHDA Model
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• What is 6-OHDA?
‒ Neurotoxin induces SNpc
neurodegeneration
• Dopaminergic selectivity
- 6-OHDA structural analog:
dopamine
-Taken into SNpc via dopamine
transporters (DAT)
http://openi.nlm.nih.gov/imgs/512/250/2957224/2957224_PD2010-427810.002.png
Before
After

5. • Mechanism of neurotoxicity
- Degradation by MAO
- Generates H2O2, free radicals
- Inhibits mitochondrial complex I
• Why model PD?
- No cure, limited treatments
- Better understand pathology
- Develop drugs: pre-clinical trials
6-OHDA Model of PD
http://www.sciencedirect.com/science/article/pii/S030100820100003

6. Method of implementation
• Stereotaxic surgery
– Direct injections striatum
– Unilateral vs bilateral injections
• Retrograde degeneration of SNpc
– Mimics PD: humans
• Subjects
– 9 mice injected w/ 3 mg/kg 6-OHDA
– 3 controls injected with saline
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7. Motor Outputs
Left Brain Right Brain
Controls left
side of body
Controls right
side of body
6-OHDA lesion
Motor impairments
develop
Motor function
unaffected
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8. Onset: PD Phenotypes
• Successful model: replicates phenotypes
- Symptoms typically emerge within weeks
• Conduct behavioral assays
- Assess degree motor deficits develop
• Establish SOP’s: behavioral tests
-Ensure protocols run smoothly
http://www.nature.com/nrn/journal/v10/n7/fig_tab/nrn2652_F1.html8

9. Behavioral Assays: Overview
Rotarod Test
Adhesive Removal Test
Forelimb Rearing Test
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10. Rotarod Test
• Assesses coordination,
balancing abilities
• Rod acceleration: 4-40 rpm
• Walked 300s, rested: 15 min
intervals
• Record time spent continuously
walking
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(3 weeks post injection)

11. Rotarod in Action
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12. Data Collection/Results
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13. 13
Rotarod Performance: 6-OHDA groups vs control
(training period)
180
190
200
210
220
230
240
250
260
270
280
7/29 7/30 7/31
6-OHDA
groups
Control group
AverageTimewalked(s)
Dates

14. 14
215
220
225
230
235
240
245
250
255
260
265
7/29 8/5
6-OHDA groups
Control group
Rotarod Performance: 6-OHDA groups vs control
AverageTimewalked(s)
Dates

15. Adhesive Removal Test
• Measure sensorimotor deficits
• Adhesives: alternately applied
• Left, right forepaw
• Measure time: sense, remove
adhesives
• Mice affected by 6-OHDA
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Sticker

16. Forelimb Rearing Test
• Assess forelimb motor impairment
• Placed glass cylinder
• Note forelimb favored: when rearing
• Record frequency use:
• Left, right or both forelimbs
• Mice affected by 6-OHDA:
• Ipsilateral forelimb dependence
Forelimb Rearing Test
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17. Modeling Alzheimer’s
Disease (AD)
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18. Morris Water Maze
• Alzheimer’s disease behavioral
assay
• Tests spatial learning/memory
• Developed SOP’s
• Protocol runs smoothly
• Establish appropriate environment
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19. MWM Procedure
▪ Mice swim in tub: opaque water
▪ Find submerged platform
▪ Visual cues posted: walls
▪ Released: four different
directions
▪ Factors of importance
NW
W
SE
SW
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20. Conclusions
▪ Early stages: developing PD
phenotypes
▪ SOP’s: identify, correct
interfering factors
▪ Lack training
▪ Timing: trials
▪ Mouse behaviors
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21. Acknowledgements
▪ My appreciation to:
 Dr. Huang for her guidance
 National Animal Laboratory
Center, NARLabs
 The mouse subjects
▪ Thank you all!
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