Temporal changes of astrocyte activation and glutamate transporter-1 expression in the spinal cord after spinal nerve ligation-induced neuropathic pain.
Astrocyte activation is involved in the neuropathic pain. As a glutamate scavenger, the glutamate transporter-1 (GLT-1) is exclusively expressed on the astrocytes and probably correlates with astrocyte activation. In the present study, we attempted to clarify the temporal changing courses of astrocyte activation and GLT-1 expression, as well as their correlations induced by a neuropathic pain model, namely, spinal nerve ligation (SNL) in which rapidly appearing (<3 days) and persistent (>21 days) mechanical allodynia and thermal hyperalgesia were presented. Immunofluorescent staining showed that GLT-1 was expressed exclusively in most (not all) of the astrocytes, even when the GLT-1 expression reached its peak. The expression of GLT-1 displayed an interesting biphasic change, with an initial up-regulation followed by a down-regulation after SNL. Our results also demonstrated that SNL induced a marked and long-term (>21 days) activation of astrocytes in the ipsilateral spinal dorsal horn. These results suggest that astrocyte activation, the change of GLT-1 expression and the potential relationship between them might play key roles in the induction and/or maintenance of neuropathic pain. The present results provide novel clues in understanding the mechanisms underlying the involvement of astrocytes and GLT-1 in the neuropathic pain.
Wang
Wei
W
Department of Anatomy, The Fourth Military Medical University, Xi'an, People's Republic of China.
Wang
Wen
W
Wang
Yayun
Y
Huang
Jing
J
Wu
Shengxi
S
Li
Yun-Qing
YQ
D000818:Animals; D001253:Astrocytes / Q000378:metabolism*; D001522:Behavior, Animal / Q000502:physiology*; D027342:Excitatory Amino Acid Transporter 2 / Q000378:metabolism*; D008026:Ligation; D008297:Male; D009437:Neuralgia / Q000378:metabolism* / Q000503:physiopathology; D051381:Rats; D017207:Rats, Sprague-Dawley; D013116:Spinal Cord / Q000378:metabolism*; D013997:Time Factors
D027342:Excitatory Amino Acid Transporter 2