Single-channel currents recorded from membrane of denervated frog muscle fibres

  title={Single-channel currents recorded from membrane of denervated frog muscle fibres},
  author={Erwin Neher and Bert J. Sakmann},
THE ionic channel associated with the acetylcholine (ACh) receptor at the neuromuscular junction of skeletal muscle fibres is probably the best described channel in biological membranes. Nevertheless, the properties of individual channels are still unknown, as previous studies were concerned with average population properties. Macroscopic conductance fluctuations occurring in the presence of ACh were analysed to provide estimates for single channel conductance and mean open times1–3. The values… 

Acetylcholine activates single sodium channels in smooth muscle cells

From features of the macroscopic and single channel currents, it is concluded that these muscarinic ACh(CCh)-activated channels mainly pass Na ion and play a major part in the membrane depolarization produced by ACh or CCh in mammalian intestinal smooth muscles.

Single postsynaptic channel currents in tissue cultured muscle

Measurements of single-channel currents induced by the agonist carbamylcholine in tissue-cultured mammalian muscle confirm the earlier noise studies on tissue culture preparations.

Developmental changes in acetylcholine receptor channel properties of vertebrate skeletal muscle.

In 1972 Katz and Miledi reported by analyzing the acetylcholine (ACh)-induced voltage noise in frog skeletal muscle that the elementary voltage changes were greater in denervated muscle than in innervated Muscle, the first indication that two types of channels exist in adult frog muscle following denervation.

Single channel properties of newly synthesized acetylcholine receptors following denervation of mammalian skeletal muscle

These data argue against the proposal that, in denervated muscle, the low- conductance channels undergo continued conversion to the high-conductance type focally at the site of former synaptic contact and provide additional support for the idea that the functional properties of ACh receptors are governed uniformly by the state of innervation of the fiber.

Fluctuations in the microsecond time range of the current through single acetylcholine receptor ion channels

Results obtained with the acetylcholine-like agonist, suberyldicholine, suggest that the brief gaps do not result from ion channel block by the agonist itself, but which are consistent with a mechanism in which the channel opens and closes several times during a single agonist receptor occupancy.

Discrete Current Fluctuations Produced by Single K+-Channels in the Squid Axon Membrane

A modification is described which allows high-resolution measurements to be made on the squid axon membrane with sufficient resolution to resolve unitary events of this magnitude.

Properties of single potassium channels in vesicles formed from the sarcolemma of frog skeletal muscle.

The patch‐clamp method was used to study unitary delayed rectifier K+ channels in large vesicles formed from the membrane of frog skeletal muscle, and results imply a scheme with at least three closed states, an open and an inactivated state.

Single-channel currents in isolated patches of plasma membrane from basal surface of pancreatic acini

Measurements of single-channel currents from isolated patches of plasma membrane (inside-out) from the baso-lateral surface of collagenase-isolated rat and mouse pancreatic acini identify a cation channel having a conductance of ∼30 pS and a mean open time in the range 0.3–1 s which is dependent on internal calcium.



Relaxation spectra of potassium channel noise from squid axon membranes.

  • H. M. Fishman
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1973
By comparison of the values of f(c) from relaxation spectra of membrane channel noise with those from calculated (Hodgkin-Huxley equations) power spectra, it is possible to relate and compare channel models that previously could only be applied to macroscopic potassium conductance data.

Conductance of channels opened by acetylcholine-like drugs in muscle end-plate

This work has estimated average single channel conductances for four cholinomimetic agonists, and finds this prediction that a channel, once it is open, will have the same conductance whichever drug caused it to open is not confirmed.

Discreteness of Conductance Change in Bimolecular Lipid Membranes in the Presence of Certain Antibiotics

NET ion movements across biological or synthetic lipid membranes may take place by various mechanisms, underlying all of which there is a rather ill-defined and small ion leakage or background

Impedance of a Small Electrically Isolated Area of the Muscle Cell Surface

The frequency dependence of the muscle cell membrane capacity found earlier by other methods has been confirmed and the internal phase angle of the complex impedance plot of whole muscle probably does not result from a distribution of fiber diameters and membrane capacities.

Active phase of frog's end-plate potential.

The purpose of the present experiment was to determine directly the time course of the active phase of the e.

Voltage clamp analysis of acetylcholine produced end‐plate current fluctuations at frog neuromuscular junction

1. Acetylcholine produced end‐plate current (e.p.c.) noise is shown to be the results of statistical fluctuations in the ionic conductance of voltage clamped end‐plates of Rana pipiens.

The characteristics of ‘end‐plate noise’ produced by different depolarizing drugs

1. End‐plate depolarization and associated ‘membrane noise’ due to decamethonium, acetylthiocholine and suberyldicholine have been examined and compared with the effects of acetylcholine and

The statistical nature of the acetylcholine potential and its molecular components

1. When a steady dose of acetylcholine is applied to an end‐plate, the resulting depolarization is accompanied by a significant increase in voltage noise, and this noise can be significant in both the positive and the negative directions.

Effects of proteolytic enzymes on function and structure of frog neuromuscular junctions

1. Frog cutaneous pectoris nerve‐muscle preparations were incubated with collagenase and protease and examined with electrophysiological and electron microscopic techniques.