Paper Info
Title
Modeling the leech heartbeat elemental oscillator I. Interactions of intrinsic and synaptic currents
Abstract
We have developed a biophysical model of a pair of reciprocally inhibitory interneurons comprising an elemental heartbeat oscillator of the leech. We incorporate various intrinsic and synaptic ionic currents based on voltage-clamp data. Synaptic transmission between the interneurons consists of both a graded and a spike-mediated component. By using maximal conductances as parameters, we have constructed a canonical model whose activity appears close to the real neurons. Oscillations in the model arise from interactions between synaptic and intrinsic currents. The inhibitory synaptic currents hyperpolarize the cell, resulting in activation of a hyperpolarization-activated inward currentIh and the removal of inactivation from regenerative inward currents. These inward currents depolarize the cell to produce spiking and inhibit the opposite cell. Spike-mediated IPSPs in the inhibited neuron cause inactivation of low-threshold Ca++ currents that are responsible for generating the graded synaptic inhibition in the opposite cell. Thus, although the model cells can potentially generate large graded IPSPs, synaptic inhibition during canonical oscillations is dominated by the spike-mediated component.
Year
DOI
Venue
1995
10.1007/BF00961435
Journal of Computational Neuroscience
Keywords
Field
DocType
central pattern generator,half-center oscillator
Hyperpolarization (biology),Heartbeat,Neuroscience,Neurotransmission,Leech,Inhibitory postsynaptic potential,Depolarization,Neuron,Central pattern generator,Mathematics
Journal
Volume
Issue
ISSN
2
3
0929-5313
Citations 
PageRank 
References 
15
5.11
2
Authors
4
Name
Order
Citations
PageRank
Farzan Nadim16820.17
Øystein H. Olsen2229.81
Erik De Schutter330750.62
Ronald L. Calabrese49024.40