Responses of rat P2X2 receptors to ultrashort pulses of ATP provide insights into ATP binding and channel gating.

ABSTRACT: To gain insight into the way that P2X(2) receptors localized at synapses might function, we explored the properties of outside-out patches containing many of these channels as ATP was very rapidly applied and removed. Using a new method to calibrate the speed of exchange of solution over intact patches, we were able to reliably produce applications of ATP lasting <200 micros. For all concentrations of ATP, there was a delay of at least 80 micros between the time when ATP arrived at the receptor and the first detectable flow of inward current. In response to 200-micros pulses of ATP, the time constant of the rising phase of the current was approximately 600 micros. Thus, most channel openings occurred when no free ATP was present. The current deactivated with a time constant of approximatel

SUBMITTER: Moffatt L 

PROVIDER: S-EPMC2151634 | biostudies-literature | 2007 Aug

REPOSITORIES: biostudies-literature