title: Co-expression of heat sensitive vanilloid receptor subtypes in rat dorsal root ganglion neurons.
abstract: Expression of the heat sensitive cation channels TRPV1 and TRPV2 was investigated by immunofluorescence in rat dorsal root ganglion (DRG) neurons. TRPV1-positive neurons were more frequent and had smaller diameters than TRPV2-positive neurons (35.7% vs 7.3%; 22.3 microm vs 27.6 microm), but size distributions overlapped and significant co-expression was seen in 20.7% of TRPV2-positive neurons (1.7% of all). Expression patterns did not differ between tissue sections typically used in immunocytochemistry and dissociated DRG neurons typically used in electrophysiology. Rectangular temperature pulses revealed two patterns of heat-evoked inward currents in small DRG neurons: low-threshold rapidly activating and high-threshold slowly activating. Slowly activating heat-evoked currents have not been described previously, but correspond to the type I heat responses of primary nociceptive afferents, which have been suggested to be mediated by TRPV2.
authors: Institute of Physiology and Pathophysiology, Johannes Gutenberg University, Mainz, Germany.
authors: Wolfgang
authors: W
authors: Greffrath
authors: Uta
authors: U
authors: Binzen
authors: Stefan T
authors: ST
authors: Schwarz
authors: Sigrid
authors: S
authors: Saaler-Reinhardt
authors: Rolf-Detlef
authors: RD
authors: Treede
mesh_terms: D000818:Animals; D005727:Ganglia, Spinal / Q000378:metabolism*; D005786:Gene Expression Regulation / Q000502:physiology; D006358:Hot Temperature; D009474:Neurons / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D011955:Receptors, Drug / Q000096:biosynthesis*; D050916:TRPV Cation Channels
chemical_list: D011955:Receptors, Drug; D050916:TRPV Cation Channels; C494484:TRPV1 receptor