[Abstract Title]. - Society for Neuroscience

temporal and spatial expression of MAP kinases and MKPs in ipsilateral and contralateral
trigeminal ganglion cells in response to unilateral capsaicin injection into the TMJ capsule.
Capsaicin stimulation of V3 trigeminal nerves at 2 hrs was found to increase the nuclear
expression of the MAP kinase protein p38 in both neurons and satellite glial cells, but not
Schwann cells. In contrast, increased levels of ERK were only observed in the nucleus of
neuronal cells, but not glial cells, 2 hrs after capsaicin injection. The levels of p38 and ERK
staining were greater in the ipsilateral ganglion when compared to contralateral ganglion at the 2
hrs. By 24 hrs post injection, p38 and ERK levels had returned to basal levels. Somewhat
surprisingly, no increase in JNK staining was observed in either neurons or glia in response to
capsaicin stimulation. MKP-1 expression was readily detected in satellite glial cells but not
neuronal cells under basal conditions. In response to capsaicin, MKP-1 levels were increased
similarly in both neurons and satellite glial cells in both ipsilateral and contralateral ganglion 2
hrs after injection and then remained elevated even after 24 hrs. However, elevated levels of
MKP-2 and MKP-3 were only observed in neurons in both ganglia at 2 and 24 hrs post injection.
In summary, we have shown that stimulation of trigeminal neurons that provide sensory
innervation of the TMJ leads to increased levels of active p38 and ERK MAP kinases as well as
a sustained induction of MKPs in all regions of the ipsilateral and contralateral ganglia. We
propose that the induction of MKPs in response to capsaicin injection into the TMJ capsule plays
an important role in regulating neuronal gene expression in response to acute inflammatory
stimuli by decreasing expression of active MAP kinases to basal levels in both neurons and
satellite glial cells.
Disclosures: P.L. Durham, NIH DE017805, B. Research Grant (principal investigator,
collaborator or consultant and pending grants as well as grants already received); S. Thalakoti,
None.
Poster
241. Glial Neuronal Interactions
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 241.6/F12
Topic: B.11.b. Cell biology and signalling
Support: New York State Spinal Cord Injury Research Board
NIH Grant CA128158-12
Title: GFAP-expressing astrocytes respond to sonic hedgehog signaling in the adult CNS