Impaired pain sensation in mice lacking Aquaporin-1 water channels.
Aquaporin-1 (AQP1), a membrane water channel, is expressed in choroid plexus where it contributes to cerebrospinal fluid production. Here, we show that AQP1 is also expressed in the dorsal horn of the spinal cord and the trigeminal nucleus caudalis, regions that process pain information. Within the dorsal root and trigeminal sensory ganglia, AQP1 is concentrated in small diameter cell bodies, most of which give rise to unmyelinated C-fibers. To study the role of AQP1 in pain signaling, we compared acute pain responses in wild-type mice and in mice lacking AQP1. AQP1(-/-) mice had reduced responsiveness to thermal and capsaicin chemical stimuli, but not to mechanical stimuli or formalin. These results provide evidence for AQP1 expression in nociceptive neurons and suggest that AQP1 may play a role in pain signal transduction.
Department of Neurosurgery, University of California-San Francisco, San Francisco, CA 94143, USA.
Kotaro
K
Oshio
Hiroyuke
H
Watanabe
Donghong
D
Yan
A S
AS
Verkman
Geoffrey T
GT
Manley
D000818:Animals; D051398:Aquaporin 1 / Q000172:deficiency / Q000502:physiology*; D002211:Capsaicin / Q000494:pharmacology; D002831:Choroid Plexus / Q000737:chemistry; D005727:Ganglia, Spinal / Q000502:physiology; D006358:Hot Temperature; D051379:Mice; D018345:Mice, Knockout; D010146:Pain / Q000503:physiopathology; D017288:Pain Threshold / Q000502:physiology*; D020671:Posterior Horn Cells / Q000502:physiology; D015398:Signal Transduction
C496021:Aqp1 protein, mouse; D051398:Aquaporin 1; D002211:Capsaicin