1. Membrane currents during step depolarizations were determined by a method in which three electrodes were inserted near the end of a fibre in the frog's sartorius muscle. The theoretical basis and limitations of the method are discussed.2. Measurements of the membrane capacity (C(M)) and resting resistance (R(M)) derived from the current during a step change in membrane potential are consiste...

The voltage clamp technique is frequently used to examine the strength and composition of synaptic input to neurons. Even accounting for imperfect voltage control of the entire cell membrane ("space clamp"), it is often assumed that currents measured at the soma are a proportional indicator of the postsynaptic conductance. Here, using NEURON simulation software to model somatic recordings from ...

These studies have developed and tested an experimental approach to the study of membrane ionic conductance mechanisms in strips of uterine smooth muscle. The experimental and theoretical basis for applying the double sucrose-gap technique is described along with the limitations of this system. Nonpropagating membrane action potentials were produced in response to depolarizing current pulses un...

• Although voltage clamp methods have been applied experimentally to cardiac tissue for over a decade, this field of study has failed to achieve general acceptance because of limitations of the experimental approach and difficulty in interpreting the results. Yet this technique is valuable within its limitations, and to dismiss it would be to lose a valuable tool. In perspective, most technique...

Probably the most striking and surprising observation in internally perfused axons is that full-sized action potentials can be obtained in the face of a very low resting potential when the ionic strength is low In all experiments at normal ionic strength known to the author, the explosive all-or-none responsiveness was lost when the internal and/or external monovalent cations were arranged to g...