Dorsal root ganglion neurons respond with prolonged extracellular signal-regulated protein kinase phosphorylation following noxious heat and cold stimulation

作者：Donnerer Josef^*; Liebmann Ingrid

来源：Neuroscience Letters, 2010, 472(2): 109-113.

DOI：10.1016/j.neulet.2010.01.064

• Intracellular signalling
• ERK1/2 phosphorylation
• TRP channels
• Western blotting
• Immunohistochemistry

In the present study the time course of extracellular signal-regulated protein kinase phosphorylation (pERK1/2 appearance) in lumbar sensory dorsal root ganglia (DRG) was determined following a 5-min noxious heat or a noxious cold stimulus to the hind paw of the rat. The thermal stimuli were chosen to activate transient receptor potential (TRP) channels, but not to induce tissue damage. A quantitative analysis of phospho-ERK1/2 was performed by protein extraction and Western blot analysis. Western blot analysis showed that following the heat stimulus, phosphorylation of ERK1/2 increased 2-3-fold between 10 and 30 min in the DRG on the ipsilateral side. High levels were maintained from 30 min up to 16h. Following the cold stimulus to the paw, pERK1/2 immediately increased 2-fold within 2 min in the DRG on the ipsilateral side, it declined within 2 h and reached a second peak at 4 h. In the DRGs on the contralateral side of the paw's heat or cold immersion the pERK1/2 remained low at all time points investigated. Fluorescence immunohistochemistry of the DRG following the thermal stimuli revealed an increased cytoplasmic staining for pERK1/2 in neurons. The present results show that following a 5-min nociceptive thermal stimulus sensory neurons respond with a characteristic long-lasting phosphorylation of ERK1/2.

• 出版日期2010-3-19