Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Neural Conduction”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 1,297 records · Page 72Linked to original sources
PubMed1980

Mechanical hyperventilation: effect on specialized atrioventricular conduction, supraventricular refractoriness, and experimental atrial arrhythmias in dogs anesthetized with pentobarbital or pentobarbital-halothane.

The effect of hypocapnia (PCO2ET 25 vs 40 torr) on specialized atrioventricular (AV) conduction, supraventricular refractory periods, and experimental atrial arrhythmias provoked by premature atrial stimulation (atrial echoes-echoes, repetitive atrial firing (RAF)) was assessed in dogs anesthetized with pentobarbital or pentobarbital-halothane (1.0% end-tidal). Catheter His bundle electrocardiography was used. Both hypocapnia and halothane prolonged AV nodal conduction, but the effect of halothane was more pronounced. Halothane prolonged the atrial functional (AtFRP), atrial effective (AtERP), and AV nodal functional refractory (AVFRP) periods. These effects of halothane were linked to an increased incidence of RAF but not to echoes. Hypocapnia prolonged the AVFRP (less than halothane), had no effect on the AtFRP and shortened the AtERP. These effects of hypocapnia were associated with an increased incidence of echoes, but not with RAF. Echoes and RAF are thought to be caused by reentry within the sinus node, atria, and AV node. The differing effects of halothane and hypocapnia on the incidence of these arrhythmias may be due to differning effects on supraventricular refractoriness.

Anesthesia↗
PubMed1985

Longitudinal brainstem axons mediating circling: behavioral measurement of conduction velocity distributions.

Current applied near the midline brainstem elicits rapid ipsiversive circling. Pontine and midbrain sites were stimulated concurrently with paired pulses and the number of pulse pairs required to produce 3 complete circles in 10 s was measured at various intrapair (C-T) intervals. The same results were obtained when C pulses were presented via the midbrain electrode and T pulses via the pontine electrode, or vice versa: as C-T interval increased from 0.4 to 2.0 ms, the number of pulse pairs required decreased gradually. These decreases occurred at longer C-T intervals than the refractory period decreases observed in single-electrode tests. These results imply that collision occurred in the directly stimulated axons and that a longitudinal bundle of uninterrupted axons mediates the circling behavior. The sites from which collision was obtained overlap with both medial longitudinal fasciculus and crossed tectobulbar and tectospinal tracts. The axons mediating circling appear to have conduction velocities from 2 to roughly 20 m/s. By comparison, superior colliculus units antidromically driven from contralateral electrode sites that produce circling had conduction velocities from 0.7 to 40 m/s.

Animals↗
PubMed1964

EFFECT OF DETERGENT ON ELECTRICAL PROPERTIES OF SQUID AXON MEMBRANE.

The effects of detergents on squid giant axon action and resting potentials as well as membrane conductances in the voltage clamp have been studied. Anionic detergents (sodium lauryl sulfate, 0.1 to 1.0 mM; dimethyl benzene sulfonate, 1 to 20 mM, pH 7.6) cause a temporary increase and a later decrease of action potential height and the value of the resting potential. Cationic detergent (cetyl trimethyl ammonium chloride, 6 x 10(-5)M or more, pH 7.6) generally brings about immediate and irreversible decreases in the action and resting potentials. Non-ionic detergent (tween 80, 0.1 M, pH 7.6) causes a slight reversible reduction of action potential height without affecting the value of the resting potential. Both anionic and cationic detergents generally decrease the sodium and potassium conductances irreversibly. The effect of non-ionic detergent is to decrease the sodium conductance reversibly, leaving the potassium conductance almost unchanged.

Action Potentials↗