Learn More
How is the short-term memory for a single form of learning distributed among the various elements of a neuronal circuit? To answer this question, we examined the short-term memory for sensitization, using the siphon component of the defensive gill- and siphon-withdrawal reflex. We found that the memory for short-term sensitization is represented by at least(More)
We examined the responsivity of dentate gyrus granule cells to perforant path stimulation during classical conditioning of the rabbit nictitating membrane response. Dentate field potentials elicited by perforant path stimulation were recorded during training to test for changes in granule cell responsivity. Results showed above-baseline increases in dentate(More)
We developed a multicompartmental Hodgkin-Huxley model of the Hermissenda type-B photoreceptor and used it to address the relative contributions of reductions of two K+ currents, IA and IC, to changes in cellular excitability and synaptic strength that occur in these cells after associative learning. We found that reductions of [symbol: see text] C, the(More)
Because the Hermissenda eye is relatively simple and its cells well characterized, it provides an attractive preparation for detailed computational analysis. To examine the neural mechanisms of learning in this system, we developed multicompartmental models of the type-A and type-B photoreceptors, simulated the eye, and asked three questions: First, how do(More)
We studied the use of physiologically based, multisite, intrafascicular electrical stimulation of the sciatic nerve to achieve ripple-free contractions and sustained, fatigue-resistant forces over a physiological range of forces in cat gastrocnemius muscle. Electrode arrays containing 100, 0.5-1.5-mm-long penetrating microelectrodes were inserted into the(More)
Functional electrical stimulation (FES) is a general term for therapeutic methods that use electrical stimulation to aid or replace lost ability. For FES systems that communicate with the nervous system, one critical component is the electrode interface through which the machine-body information transfer must occur. In this paper, we examine the influence(More)
Gamma-aminobutyric acid (GABA) is a prevalent neurotransmitter in both vertebrate and invertebrate systems. Here we report that, in addition to its usual inhibitory actions, GABA induced synaptic facilitation at type B to A photoreceptor connections of the marine mollusk Hermissenda when applied transiently to the isolated nervous system. Synaptic(More)
Electrophysiological recording of neuronal unit activity during paired training trials from various regions of the ipsilateral cerebellum in rabbits well trained in the classically conditioned eyelid/nictitating membrane response have revealed both stimulus-evoked responses and responses that form an amplitude/temporal model of the learned behavioral(More)
Rabbits were overtrained using classical conditioning of the rabbit nictitating membrane (NM)/eyelid response. Unilateral electrolytic lesions were then made through electrodes previously implanted in dentate and interpositus cerebellar nuclei ipsilateral to the trained (left) eye. Lesions caused a complete or near-complete abolition of conditioned(More)
Aplysia siphon sensory cells exhibit heterosynaptic facilitation of transmitter release during both sensitization and classical conditioning of the siphon withdrawal response. In the present study, we asked whether facilitation must invariably enhance transmission at all terminals of a neuron or whether facilitation can instead occur at one set of terminals(More)