[Abstract Title]. - Society for Neuroscience

glutamate transporter EAAT2 is the main mediator of glutamate
clearance to terminate glutamate-mediated responses. Transgenic mice
over-expressing human EAAT2 (EAAT2 mice), which exhibited a 1.4-2.5
fold enhanced glutamate uptake, showed 30% less writhing response to
intraperitoneal acetic acid than nontransgenic littermates. Moreover,
EAAT2 mice showed a 50-63% reduction in visceromotor response (VMR) to colo-rectal
distension (CRD) when assessing the response to 15- 60
mmHg pressures. Corroborating the involvement of enhanced glutamate
uptake, wild-type mice treated for 1 week with ceftriaxone (200mg/kg
daily), a stimulator of EAAT2 expression, showed a 52-70% reduction in
VMR to graded increases in colo-rectal distension. The data suggest
that enhanced glutamate uptake provides protective effects against
mechanical distension-induced pain. Future studies will explore 1) the
physiological site and mechanism by which enhanced glutamate transport
activity mediates the antinociceptive effect and 2) enhanced glutamate
transport effects on inflammogen-augmented visceral pain response.
Disclosures: Y. Lin, None; J. Travers, None; R. Stephens, None; G. Lin, None.
Poster
269. Pain: Visceral Pain II
Time: Sunday, November 16, 2008, 1:00 pm - 5:00 pm
Program#/Poster#: 269.3/GG18
Topic: D.08.n. Visceral pain
Support: Science Foundation Ireland
GlaxoSmithKline
IDA Ireland
Title: Altered spinal expression of the astrocytic glutamate transporter EAAT1 in the rat
maternal separation model of visceral hypersensitivity
Authors: *R. D. GOSSELIN, N. DWYER, P. FITZGERALD, T. G. DINAN, J. F. CRYAN;
Univ. Col. Cork, Cork, Ireland
Abstract: Alterations in gastrointestinal function and elevations in visceral pain in adulthood
represent one of the most troublesome consequences of early-life stress. However, the molecular