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Why pain?

  1. Most common reason to seek medical attention: pain.

  2. Low success in translating laboratory findings to treatments for patients.

  3. Need for an objective method to measure "pain", a subjective experience.

Comparison of analgesic drugs

for osteoarthritis across species

comparison of analgesic drugs

TBD: To Be Determined


Functional magnetic resonance imaging (fMRI)

deoxygenated hemoglobin

Deoxygenated hemoglobin

(Paramagnetic - decreasing magnetic resonance signals)

Decreasing blood flow
oxygenated hemoglobin

Oxygenated hemoglobin


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


PAG periaqueductal grey

S2 secondary somatosensory area


brain activity
High brain activity

Nature Reviews Neurology 5(4):199-209, 2009


Stimulation procedure fMRI

Minimum 10 sets (15 minutes)
CT scan
fMRI measure
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

  • Chemotherapy-induced neuropathic pain

  • Postoperative pain

  • Visceral pain

  • Sciatic nerve ligation

  • Endometriosis

Please contact us for more details concerning our NHP models and services.

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