In order to find whether presynaptic inhibition of tooth pulp afferents is enhanced in any phase of sleep or wakefulness, the orthodromic mass response of the trigeminal nucleus to electrical stimulation of the ipsilateral tooth pulp and the antidromic mass response of the tooth pulp to stimulation of the trigeminal nucleus were recorded in the cat. Both responses were stable in amplitude durin...

BACKGROUND Recently, we used a custom designed "jacket" electrode with 127 bipolar electrodes in a flexible nylon matrix to map the total atrial epicardial surface in the in situ canine heart. Atrial flutter in dogs with sterile pericarditis was shown to be due to a single wave front circulating around a combined functional/anatomic obstacle, with the arc of functional conduction block contiguo...

The fact that mecamylamine is a secondary amine with “nicotinic” blocking properties suggested it would act at the Golgi recurrent collateral-Renshaw-cell synapse in the spinal cord. Glass micropipettes were used to obtain extracellular Renshaw-cell discharges due to antidromic ventral root stimulation in cats anesthetized with pentobarbital. The effects of mecamylamine, hexamethonium, physosti...

1. In Fundulus heteroclitus the dispersing melanophore nerve fibers have a relatively high threshold for faradic stimulation and a low one for stimulation by cutting. When they are protected from the competing action of the concentrating fibers, they show through the responses of their melanophores well marked antidromic activities which can also be seen to a slight degree even where the concen...

Wall and Shortland (1991) have shown that afferent fibers entering the cord in thoracic and lumbar roots of adult rats have branches that may penetrate up to 11 segments caudally from the root entry zone. We have investigated the extent of branching and conduction velocities of ascending and descending branches of lumbar and thoracic primary afferents in isolated spinal cords of adult hamsters ...

BACKGROUND The mechanisms of common atrial flutter entrainment have not been directly studied in humans. METHODS AND RESULTS Endocardial mapping in six cases of common flutter showed large right atrial (RA) reentry circuits. Activation was craniocaudal in the anterolateral right atrium and caudocranial in the septum. The inferior vena cava-tricuspid isthmus (IVC-TV) closed the circuit. The hi...

Spikes were evoked in rat olfactory sensory neuron (OSN) populations by electrical stimulation of the olfactory bulb nerve layer in pentobarbital anesthetized rats. The latencies and recording positions for these compound spikes showed that they originated in olfactory epithelium. Dual simultaneous recordings indicated conduction velocities in the C-fiber range, around 0.5 m/sec. These spikes a...