Gated currents in isolated olfactory receptor neurons of the larval tiger salamander.
The electrical properties of enzymatically isolated olfactory receptor cells were studied with whole-cell patch clamp. Voltage-dependent currents could be separated into three ionic components: a transient inward sodium current, a sustained inward calcium current, and an outward potassium current. Three components of the outward current could be identified by their gating and kinetics: a calcium-dependent potassium current [IK(Ca)], a voltage-dependent potassium current [IK(V)], and a transient potassium current (Ia). Typical resting potentials were near -54 mV, and typical input resistance was 3-6 G omega. Thus, only 3 pA of injected current was required to depolarize the cell to spike threshold near -45 mV. The response to a current step consisted of either a single spike regardless of stimulus strength, or a train of less than 8 spikes, decrementing in amplitude and frequency over approximately equal to 250 msec. Thus, the receptor response cannot be finely graded with stimulus intensity.
D000818:Animals; D004558:Electric Stimulation; D004594:Electrophysiology; D066298:In Vitro Techniques; D007473:Ion Channels / Q000378:metabolism; D008564:Membrane Potentials; D009474:Neurons / Q000502:physiology; D009831:Olfactory Mucosa / Q000294:innervation*; D014562:Caudata / Q000502:physiology*
D007473:Ion Channels