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Axon-somatic back-propagation in detailed models of spinal alpha motoneurons.

Balbi P, Martinoia S, Massobrio P - Front Comput Neurosci (2015)

Bottom Line: An axon hillock, an axonal initial segment and a myelinated axon are added to each model.By sweeping the diameter of the axonal initial segment (AIS) and the axon hillock, as well as the maximal conductances of sodium channels at the AIS and at the soma, the developed models are able to show the relationships between different geometric and electrophysiological configurations and the voltage attenuation of the antidromically traveling wave.In particular, a greater than usually admitted sodium conductance at AIS is necessary and sufficient to overcome the dramatic voltage attenuation occurring during antidromic spike propagation both at the myelinated axon-AIS and at the AIS-soma transitions.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurorehabilitation, Scientific Institute of Pavia via Boezio, IRCCS, 'Salvatore Maugeri' Foundation Pavia, Italy.

ABSTRACT
Antidromic action potentials following distal stimulation of motor axons occasionally fail to invade the soma of alpha motoneurons in spinal cord, due to their passing through regions of high non-uniformity. Morphologically detailed conductance-based models of cat spinal alpha motoneurons have been developed, with the aim to reproduce and clarify some aspects of the electrophysiological behavior of the antidromic axon-somatic spike propagation. Fourteen 3D morphologically detailed somata and dendrites of cat spinal alpha motoneurons have been imported from an open-access web-based database of neuronal morphologies, NeuroMorpho.org, and instantiated in neurocomputational models. An axon hillock, an axonal initial segment and a myelinated axon are added to each model. By sweeping the diameter of the axonal initial segment (AIS) and the axon hillock, as well as the maximal conductances of sodium channels at the AIS and at the soma, the developed models are able to show the relationships between different geometric and electrophysiological configurations and the voltage attenuation of the antidromically traveling wave. In particular, a greater than usually admitted sodium conductance at AIS is necessary and sufficient to overcome the dramatic voltage attenuation occurring during antidromic spike propagation both at the myelinated axon-AIS and at the AIS-soma transitions.

No MeSH data available.


Fourteen detailed 3D somato-dendritic morphologies of cat spinal alpha-motoneuron imported from NeuroMorpho.org (Ascoli et al., 2007). The vertical upward neurite in each neuron represents the proximal part of the axon and was added after importing the somato-dendrite morphologies.
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Figure 1: Fourteen detailed 3D somato-dendritic morphologies of cat spinal alpha-motoneuron imported from NeuroMorpho.org (Ascoli et al., 2007). The vertical upward neurite in each neuron represents the proximal part of the axon and was added after importing the somato-dendrite morphologies.

Mentions: In the simulations, we used reconstructed 3D morphologies of dendritic tree and soma from 14 cat spinal motoneurons (Figure 1), available from the NeuroMorpho database (Ascoli et al., 2007).


Axon-somatic back-propagation in detailed models of spinal alpha motoneurons.

Balbi P, Martinoia S, Massobrio P - Front Comput Neurosci (2015)

Fourteen detailed 3D somato-dendritic morphologies of cat spinal alpha-motoneuron imported from NeuroMorpho.org (Ascoli et al., 2007). The vertical upward neurite in each neuron represents the proximal part of the axon and was added after importing the somato-dendrite morphologies.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4325909&req=5

Figure 1: Fourteen detailed 3D somato-dendritic morphologies of cat spinal alpha-motoneuron imported from NeuroMorpho.org (Ascoli et al., 2007). The vertical upward neurite in each neuron represents the proximal part of the axon and was added after importing the somato-dendrite morphologies.
Mentions: In the simulations, we used reconstructed 3D morphologies of dendritic tree and soma from 14 cat spinal motoneurons (Figure 1), available from the NeuroMorpho database (Ascoli et al., 2007).

Bottom Line: An axon hillock, an axonal initial segment and a myelinated axon are added to each model.By sweeping the diameter of the axonal initial segment (AIS) and the axon hillock, as well as the maximal conductances of sodium channels at the AIS and at the soma, the developed models are able to show the relationships between different geometric and electrophysiological configurations and the voltage attenuation of the antidromically traveling wave.In particular, a greater than usually admitted sodium conductance at AIS is necessary and sufficient to overcome the dramatic voltage attenuation occurring during antidromic spike propagation both at the myelinated axon-AIS and at the AIS-soma transitions.

View Article: PubMed Central - PubMed

Affiliation: Department of Neurorehabilitation, Scientific Institute of Pavia via Boezio, IRCCS, 'Salvatore Maugeri' Foundation Pavia, Italy.

ABSTRACT
Antidromic action potentials following distal stimulation of motor axons occasionally fail to invade the soma of alpha motoneurons in spinal cord, due to their passing through regions of high non-uniformity. Morphologically detailed conductance-based models of cat spinal alpha motoneurons have been developed, with the aim to reproduce and clarify some aspects of the electrophysiological behavior of the antidromic axon-somatic spike propagation. Fourteen 3D morphologically detailed somata and dendrites of cat spinal alpha motoneurons have been imported from an open-access web-based database of neuronal morphologies, NeuroMorpho.org, and instantiated in neurocomputational models. An axon hillock, an axonal initial segment and a myelinated axon are added to each model. By sweeping the diameter of the axonal initial segment (AIS) and the axon hillock, as well as the maximal conductances of sodium channels at the AIS and at the soma, the developed models are able to show the relationships between different geometric and electrophysiological configurations and the voltage attenuation of the antidromically traveling wave. In particular, a greater than usually admitted sodium conductance at AIS is necessary and sufficient to overcome the dramatic voltage attenuation occurring during antidromic spike propagation both at the myelinated axon-AIS and at the AIS-soma transitions.

No MeSH data available.