Odor-induced currents in Xenopus olfactory receptor cells measured with perforated-patch recording.

1. Odor-evoked currents were recorded in Xenopus laevis olfactory receptor neurons (ORNs) by the use of conventional, as well as nystatin and gramicidin-perforated, whole cell recording. The odor-evoked current ran down quickly in conventional, but not in perforated, whole cell recording. All three types of recording gave similar values for the amplitude, latency, time-to-peak, recovery time, and reversal potential of the odor-evoked current. 2. A secondary Cl current comprised a significant part of the odor-evoked current (55-65%). ECl measured by gramicidin perforation, which does not alter [Cl-]i, was -2.3 +/- 5.0 (SE) mV, indicating that these neurons maintain a high [Cl-]i and that the secondary Cl current plays an excitatory role in olfactory transduction.