Following the preceding studies on the mechanisms of excitation in stretch receptor cells of crayfish, this investigation analyzes inhibitory activity in the synapses formed by two neurons. The cell body of the receptor neuron is located in the periphery and sends dendrites into a fine muscle strand. The dendrites receive innervation through an accessory nerve fiber which has now been establish...

The purpose of this study was to define specific types of resetting responses to programmed electrical stimulation during human ventricular tachycardia and to use computer simulations of reentry circuits to assess the possible mechanisms and pacing site location relative to the reentry circuit for each type of response. The effects of scanning single stimuli at 35 left ventricular endocardial s...

The recurrent mossy fiber pathway of the dentate gyrus expands dramatically in many persons with temporal lobe epilepsy. The new connections among granule cells provide a novel mechanism of synchronization that could enhance the participation of these cells in seizures. Despite the presence of robust recurrent mossy fiber growth, orthodromic or antidromic activation of granule cells usually doe...

The caudal neurosecretory cells of two species of skate (Raia erinacea and IC. ocellata) and of the fluke (Pnralichthys dentatus) were studied by intracellular microelectrode techniques. The cells were capable of producing spikes and of being synaptically activated. The neurosecretory cells of the skate were intermingled with other neurons within the spinal cord and could not be penetrated unde...

SOME spinal motoneurons are equipped with recurrent collaterals which arise from the axon near its origin and terminate in association with other neurons of the ventral horn (cf. Cajal, 1909). An impulse that sweeps over the motor axon must also invade its collaterals. Does it then affect the excita-bility of the neurons in association with which the collaterals terminate? Miiller (1835) could ...

Short-term synaptic depression is an important component of computation within neural networks, but little is known of its contribution to information processing during synaptically generated spike trains. We analyzed short-term synaptic depression at a synapse between two identified motoneurons innervating the hind leg of the locust: the FETi-FlTi synapse (fast extensor tibiae-flexor tibiae). ...

BACKGROUND Advancement of ventricular activation by an atrial premature beat (APB) given during His bundle refractoriness followed by resetting of an antidromic tachycardia (AT) in patients with decrementally conducting accessory pathway (DAP) is a helpful maneuver to prove pathway existence and participation in the circuit. We aim to assess in a large cohort the role of APB during AT in patien...