Why pain?
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Most common reason to seek medical attention: pain.
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Low success in translating laboratory findings to treatments for patients.
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Need for an objective method to measure "pain", a subjective experience.
Comparison of analgesic drugs
for osteoarthritis across species
TBD: To Be Determined
Functional magnetic resonance imaging (fMRI)
Deoxygenated hemoglobin
(Paramagnetic - decreasing magnetic resonance signals)
Decreasing blood flow
Oxygenated hemoglobin
(Nonmagnetic)
Increasing blood flow
Once nerve cells are activated, local blood flow increases with oxygenated hemoglobin to supply oxygen, and the ratio of deoxygenated hemoglobin, which distorts local magnetic fields, decreases. This results in increased magnetic resonance signals.
High MRI signal = Brain activation
Pain-matrix
PAG periaqueductal grey
S2 secondary somatosensory area
High brain activity
Nature Reviews Neurology 5(4):199-209, 2009
Stimulation procedure fMRI
Minimum 10 sets (15 minutes)
OFF/ON 1 set:
30 sec, 10 frames
OFF : resting state
ON : pain state
After scanning, a statistical map is produced, showing areas of activation following stimulation. The brain activation is statistically calculated by analyzing "OFF" and "ON" data sets.
x : a raw score
µ : mean
σ : standard deviation
if z > 1.96, p < 0.05
fMRI can be utilized in various NHP pain models
In vivo brain activation can be observed across cynomolgus macaque-based pain models
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Chemotherapy-induced neuropathic pain
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Postoperative pain
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Visceral pain
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Sciatic nerve ligation
*Information described in this page is referred from the following publications.
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Hama et al. CNS & Neurological Disorders - Drug Targets. 2016
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Hama et al. CNS & Neurological Disorders - Drug Targets. 2013
Please contact us for more details concerning our NHP models and services.