An ultrastructural evidence for the expression of transient receptor potential ankyrin 1 (TRPA1) in astrocytes in the rat trigeminal caudal nucleus.
The transient receptor potential ankyrin 1 (TRPA1) is implicated in the mechanical and cold hyperalgesia following inflammation and nerve injury. Its expression has been presumed to be confined to primary afferent terminals. Here, we show that TRPA1 is expressed in astrocytes in the superficial laminae of the rat trigeminal caudal nucleus by use of electron microscopic immunoperoxidase and immunogold labeling techniques. Immunoreactivity for TRPA1 was consistently observed in somata and process of astrocytes and was weaker than that in presumed nociceptive primary afferent terminals, but increased significantly in the fine process of astrocyte in rats with experimental inflammation of the temporomandibular joint. Thus, we provide ultrastructural evidence that TRPA1 is expressed in astrocytes in the brain stem and propose a novel pathway of its involvement in the central mechanism of inflammatory hyperalgesia.
Department of Oral Anatomy and Neurobiology, School of Dentistry, Kyungpook National University, Daegu 700-412, South Korea.
Sang Man
SM
Lee
Yi Sul
YS
Cho
Tae Heon
TH
Kim
Myoung Uk
MU
Jin
Dong Kuk
DK
Ahn
Koichi
K
Noguchi
Yong Chul
YC
Bae
D000818:Animals; D001253:Astrocytes / Q000378:metabolism* / Q000648:ultrastructure*; D007150:Immunohistochemistry; D008297:Male; D046529:Microscopy, Electron, Transmission; D051381:Rats; D017207:Rats, Sprague-Dawley; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels / Q000096:biosynthesis*; D014275:Trigeminal Caudal Nucleus / Q000378:metabolism* / Q000648:ultrastructure*
D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels; C480976:Trpa1 protein, rat