Neurochemical research
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Neurochemical research · May 2015
Activated microglia contribute to convergent nociceptive inputs to spinal dorsal horn neurons and the development of neuropathic pain.
The activation of microglia in the spinal dorsal horn following peripheral nerve injury has been reported previously, and this change has been proposed to contribute to the development of a neuropathic pain state. We recently demonstrated that peripheral nerve injury activated convergent nociceptive inputs to spinal dorsal horn neurons. The present study was designed to further examine the role of microglia in the activation of convergent nociceptive inputs as well as development of a neuropathic pain state after peripheral nerve injury. ⋯ The same minocycline treatment (day 0-7) also reduced the nerve injury-induced convergence of nociceptive inputs to spinal dorsal horn neurons, as revealed by double immunofluorescence labeling for c-Fos induced by noxious heat stimulation of the hindpaw and phosphorylated extracellular signal-regulated kinase induced by electrical stimulation of the injured tibial nerve. However, the administration of minocycline for 8 days starting 7 days after surgery did not prevent nerve injury-induced microglial activation, convergent nociceptive inputs, or tactile and thermal hypersensitivity. These results suggest that microglial activation in the early stage following peripheral nerve injury plays an important role in the anomalous convergence of nociceptive signals to spinal dorsal horn neurons and the development of neuropathic pain.
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Neurochemical research · May 2015
S100B and Glial Fibrillary Acidic Protein as Indexes to Monitor Damage Severity in an In Vitro Model of Traumatic Brain Injury.
Traumatic brain injury (TBI) is a leading and rising cause of death and disability worldwide. There is great interest in S100B and Glial Fibrillary Acid Protein (GFAP) as candidate biomarkers of TBI for diagnosis, triage, prognostication and drug development. However, conflicting results especially on S100B hamper their routine application in clinical practice. ⋯ Consequently, the total amount of GFAP released showed a strong linear relationship with the severity of injury (R(2) = 0.7662; p < 0.001). Under these experimental conditions, S100B seems to be useful in diagnosing only moderate to severe TBI-like injuries. Differently, GFAP demonstrates adequate biomarker requisites since its cellular release is affected by all grades of injury severity.