J Korean Neurosurg Soc.  2011 Feb;49(2):83-91. 10.3340/jkns.2011.49.2.83.

The Effect of Minocycline on Motor Neuron Recovery and Neuropathic Pain in a Rat Model of Spinal Cord Injury

• Cho DC
• Cheong JH
• Yang MS
• Hwang SJ
• Kim JM
• Kim CH

• KMID: 1442612
• DOI: http://doi.org/10.3340/jkns.2011.49.2.83

Abstract

OBJECTIVE
Minocycline, a second-generation tetracycline-class antibiotic, has been well established to exert a neuroprotective effect in animal models and neurodegenerative disease through the inhibition of microglia. Here, we investigated the effects of minocycline on motor recovery and neuropathic pain in a rat model of spinal cord injury.
METHODS
To simulate spinal cord injury, the rats' spinal cords were hemisected at the 10th thoracic level (T10). Minocycline was injected intraperitoneally, and was administered 30 minutes prior surgery and every second postoperative day until sacrifice 28 days after surgery. Motor recovery was assessed via the Basso-Beattie-Bresnahan test. Mechanical hyperalgesia was measured throughout the 28-day post-operative course via the von Frey test. Microglial and astrocyte activation was assessed by immunohistochemical staining for ionized calcium binding adaptor molecule 1 (Iba1) and glial fibrillary acidic protein (GFAP) at two sites: at the level of hemisection and at the 5th lumbar level (L5).
RESULTS
In rats, spinal cord hemisection reduced locomotor function and induced a mechanical hyperalgesia of the ipsilateral hind limb. The expression of Iba1 and GFAP was also increased in the dorsal and ventral horns of the spinal cord at the site of hemisection and at the L5 level. Intraperitoneal injection of minocycline facilitated overall motor recovery and attenuated mechanical hyperalgesia. The expression of Iba1 and GFAP in the spinal cord was also reduced in rats treated with minocycline.
CONCLUSION
By inhibiting microglia and astrocyte activation, minocycline may facilitate motor recovery and attenuate mechanical hyperalgesia in individuals with spinal cord injuries.

Keyword

Spinal cord injury; Minocycline; Astrocyte; Microglia

MeSH Terms

Animals
Astrocytes
Calcium
Extremities
Glial Fibrillary Acidic Protein
Horns
Hyperalgesia
Injections, Intraperitoneal
Microglia
Minocycline
Models, Animal
Motor Neurons
Neuralgia
Neurodegenerative Diseases
Neuroprotective Agents
Rats
Spinal Cord
Spinal Cord Injuries
Calcium
Glial Fibrillary Acidic Protein
Minocycline
Neuroprotective Agents