Pain

Nocioception involves many neural systems in the brain and spinal cord (e.g. opiates, neuropeptide Y, serotonin, NMDA, GABA, etc.). Subtle changes in any of these systems (by pharmacological or genetic manipulation) may lead to changes in the sensitivity or threshold for stimuli.

PowerPoint Presentation outlining additional validation data for Pain

  • Tail Flick
    The tail flick test measures the thermal response threshold of restrained animals through an infrared heat source.
    The Effect of Morphine on the Tail Flick Assay
    Click here to see a larger image.
  • Hot Plate and Plantar Tests
    The hot plate and plantar tests measure the thermal threshold. These tests and the tail flick are used to assess differences in the threshold between phenotypes and to test the analgesic or hyperalgesic properties of compounds.
  • Chemical-Induced Inflammatory Pain (Formalin, Carageenan)
    A sub-plantar administration of a chemical irritant such as formalin or carageenan measures nociception and inflammation in mice. These tests are useful in determining efficacy of steroidal and non-steroidal anti-inflammatory drugs and opiates.
  • Models of Neuropathic Pain (Bennett and Chung)
    Neuropathic pain is a prevalent human chronic pain disorder affecting 1.6% of the population. It is caused by damage to peripheral somatosensory nerves resulting in chronic pain in response to otherwise innocuous stimuli. This condition is extremely difficult to manage because of the lack of effect of standard analgesics. Two different neuropathic pain models, the sciatic nerve injury model (Bennett) and spinal nerve injury model (Chung), have been developed and successfully used to test therapeutic compounds.
  • Writhing
    An intraperitoneal injection of acetic acid or phenylquinone induces a transient state of somatic (visceral) pain. The ability of putative analgesic compounds to block the physiological response is measured.

    Click here to see larger image.

Back to Top