Cyclic nucleotide‐activated channels in the frog olfactory receptor plasma membrane

Abstract

Patch clamp technique was used to record cyclic nucleotide-dependent current of the frog olfactory receptor cell plasma membrane. Data obtained indicate that the channels passing this current are permeable to Ca²⁺ or Mg²⁺ and moderately selective for monovalent cations according to the sequence Li⁺, Na⁺, K⁺ > Rb⁺ > Cs⁺ and are effectively blocked by 1-cis-diltiazem and 3′,4′-dichlorobenzamil. The conductance of single cyclic nucleotide-gated channels in solutions with low Ca²⁺ and Mg²⁺ content is about 19 pS. The results demonstrate that cyclic nucleotide-activated channels of olfactory receptor cells are virtually identical to photoreceptor ones.