We calculated the wavelength of the atrial impulse in chronically instrumented conscious dogs by measuring both conduction velocity and refractory period: wavelength = refractory period X conduction velocity. Implantation of multiple stimulating and recording electrodes allowed wavelength determination at four different areas: the right and left parts of Bachmann's bundle and the free walls of ...

Studies in experimental diabetic rat attribute the acute reversible nerve conduction defect as well as the early structural abnormalities of the node of Ranvier and myelinated axons to changes in nerve metabolism secondary to hyperglycaemia and activation of the pol yo1 pathway.’-8 The early readily reversible slowing of nerve conduction velocity in the diabetic rats correlates with a decrease ...

BACKGROUND Myocardial conduction depends on intercellular transfer of current at gap junctions. Atrial myocytes express three different gap junction channel proteins-connexin43 (Cx43), connexin45 (Cx45), and connexin40 (Cx40)-- whereas ventricular myocytes express only Cx43 and Cx45. However, the physiological roles of individual connexins are unknown. We have previously shown that mice heteroz...

Lidocaine is a commonly used antiarrhythmic drug that causes use-dependent blockade of sodium channels in vitro and reduces conduction velocity in vitro and in vivo. According to the modulated receptor hypothesis of antiarrhythmic drug action, lidocaine has a low affinity for rested sodium channels but a high affinity for open and inactivated channels. In the present experiments, we characteriz...

BACKGROUND Visual stimuli elicit action potentials in tens of different retinal ganglion cells. Each ganglion cell type responds with a different latency to a given stimulus, thus transforming the high-dimensional input into a temporal neural code. The timing of the first spikes between different retinal projection neurons cells may further change along axonal transmission. The purpose of this ...

F-waves, one of the late responses produced by antidromic activation of Motoneurons by supramaximal stimulation, are one of the most frequently used studies in clinical neurophysiology. They are particularly useful for the diagnosis of proximal nerve lesions and have been found of use in diagnosis of certain types of peripheral neuropathy such as Guillian Barre Syndrome GBS, when other nerve co...

With the current practice of measuring thresholds for warming and cooling separately, the question of the exact nature of afferents subserving these sensations assumes new importance. Experiments to measure reaction times to warming and cooling stimuli at two sites on the lower limb are described. The conduction velocity for each sensation was estimated from the conduction distance and conducti...

The interaction of thermal radiation with conduction and laminar natural convection in a vertical circular pin, situated at participating gas, is numerically investigated. An absorbing and emitting gas is considered, and treated to be a gray participating media. Under the idealizing of gray gas, the Rosselan4 approximation is employed to describe the radiative heat flux in the energy equation. ...

The aim of this study was to test the reliability of the commonly used blocking technique for measuring the conduction velocity spectrum of the peripheral motor nerve in man, as first described by Hopf in 1962. Electromyographic recordings were carried out with a selectivity permitting identification of single motor unit potentials. The conduction velocity of the single alpha motor axon was det...

Numerous papers on the conduction velocity of the nerve fibers have been published since the original report of Helmholtz and Baxt (1883). Among these papers, an experimental result was presented by Wagman and Lesse (1952) that the maximum conduction velocity of human ulnar nerve fibers may be attained as early as the fourth to fifth years of life and that it may not increase from these years o...