Figure 2. SA currents are insensitive to modulation by UTP.

A, example traces showing the effect of 100 μm UTP on SA currents. Neurones were clamped to −60 mV and currents were evoked by mechanical stimuli (500 ms duration) applied at 3 s intervals (black trace). UTP was present as indicated. All cells with an SA current had action potentials characteristic of nociceptors (inflection in the falling phase). B, bars represent mean SA current amplitudes measured before (control), during (UTP) and after (wash) application of UTP. Note, SA currents in the presence of UTP did not differ from those recorded under control/wash conditions (n.s., P > 0.4, Student's paired t test, n= 8).