Ionic currents of cultured olfactory receptor neurons from antennae of male Manduca sexta.

摘要: Whole-cell and single-channel voltage-clamp techniques were used to identify characterize the ionic currents of insect olfactory receptor neurons (ORNs) in vitro. The cells isolated from antennae male Manduca sexta pupae at stages 3–5 adult development maintained primary cell culture. After 2–3 weeks vitro, presumptive ORNs had resting potentials -62 +/- 12 mV (n = 18) expressed least 1 type Na+ channel 3 types K+ channels. currents, recorded whole-cell mode, reversibly blocked by 0.1 microM tetrodotoxin. predominant observed was a voltage-activated (gamma 30 pS) with characteristics similar those delayed rectifier. activity 30-pS could be inhibited application nucleotides cytoplasmic face inside-out patches membrane. relative potencies as follows: ATP greater than cGMP cAMP, an inhibition constant for Ki 0.18 mM. Raising intracellular Ca2+ concentration 5 induced opening Ca2(+)-activated 66 pS 0 mV) that low voltage sensitivity. A third, transient 12–18 activated depolarizing steps very negative potentials. Properties this “A-channel.” These results support conclusion M. differentiate vitro provide basis studying mechanisms transduction.