Fifty-one neurons in the ventrolateral part of the medulla oblongata were antidromically activated by electrical stimulation of the suprachiasmatic part of the preoptic area in urethane-anestetized, ovariectomized and estrogen-primed female rats. Two types of antidromic responses were distinguished on the basis of their spike configurations and antidromic spike latencies. One type ("fast spikes...

It was long believed that Mahaim pathways represented nodo-fascicular or nodo-ventricular connections. However, this misconception was challenged when patients underwent surgical or catheter ablation of the AV node but remained pre-excited. Electrophysiology (EP) studies showed these pathways to be right sided decrementally conducting atrio-fascicular accessory pathways with the atrium forming ...

In hippocampus, synchronous activation of CA1 pyramidal neurons causes a rapid, extracellular, population alkaline transient (PAT). It has been suggested that the plasma membrane Ca(2+)-ATPase (PMCA) is the source of this alkalinization, because it exchanges cytosolic Ca(2+) for external H(+). Evidence supporting this hypothesis, however, has thus far been inconclusive. We addressed this long-s...

Several methods for obtaining radial nerve sensory responses have been compared. A technique for antidromic latency measurement over a fixed distance most consistently produced responses which were easy to obtain, reliable and well tolerated by the subjects.

During the electrophysiologic study of 435 patients referred for evaluation of WolffParkinson-White syndrome, 42 (10%) had preexcited reciprocating tachycardia (defined as a macroreentrant tachycardia that used an accessory atrioventricular [AV] pathway for antegrade conduction). The ages of the patients ranged from 9 to 67 years (27 + 14). Thirty-three were male patients, nine female, and eigh...