[Abstract Title]. - Society for Neuroscience

potassium channel subunit Kv9.1 in DRG neurons from adult male Wistar rats. Additionally, we
examined the regulation of the subunit following peripheral nerve injury.
Using in situ hybridization, Kv9.1 mRNA was specifically detected in medium to large size
DRG neurons, but was absent from small size nociceptor neurons as identified using the markers
CGRP and IB4. Greater than 95% of large neurons (>40 κm diameter) and almost half of
medium size neurons (30-40 κm diameter) expressed Kv9.1 mRNA. All Kv9.1 positive neurons
also labelled for NF200 immunoreactivity, suggesting that they are myelinated neurons. Fourteen
days after L5 spinal nerve transection, Kv9.1 transcript levels were dramatically reduced in the
injured DRG. This down-regulation could be seen as early as 3 days post-injury and correlated
well with the development of mechanical allodynia.
Reduced Kv9.1 expression is predicted to increase excitability of DRG neurons. The specific
detection of the channel in myelinated neurons is in agreement with the observation that
following axotomy, spontaneous activity is almost exclusively recorded from injured A-fibres.
We hypothesize that the attenuation of Kv9.1 expression as early as 3 days post-injury is an
important factor in the generation of this ectopic activity.
Disclosures: C. Tsantoulas, None; G.J. Michael , None; S.B. McMahon, None; J. Grist,
None.
Poster
268. Neuropathic Pain Mechanisms: Ion Channels
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 268.16/GG13
Topic: D.08.l. Neuropathic pain: Mechanisms
Support: NIH/NINDS R01NS45594
Univ Cincinnati Millennium Fund
NIH/NINDS R01NS55860
Title: NF-kB-mediated enhancement of potassium currents by the chemokine CXCL1/growth
related oncogene in small diameter sensory neurons
Authors: *R.-H. YANG, J. A. STRONG, J.-M. ZHANG;
Univ. Cincinnati, Cincinnati, OH
Abstract: Inflammatory processes play important roles in both neuropathic and inflammatory
pain states, but the effects of inflammation per se within the sensory ganglia are not well