Poly- and Mononeuronal Innervation in a Model
for the Development of Neuromuscular Connections
A. van Ooyen & D. J. Willshaw
J. Theor. Biol. (1999) 196: 495-511.
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In the normal development of connections between motor neurons and
muscle fibres, an initial stage of polyneuronal innervation is followed
by withdrawal of connections until each muscle fibre is innervated by a
single axon. However, polyneuronal innervation has been found to persist
after prolonged nerve conduction block, in spite of the resumption of
normal neuromuscular activity.
Here we analyse in detail a model proposed for the withdrawal of nerve
connections in developing muscle, based on competition between nerve
terminals. The model combines competition for a presynaptic resource
with competition for a postsynaptic resource. Using bifurcation and
phase space analysis, we show that polyneuronal innervation, as well as
mononeuronal innervation, can be stable. The model accounts for the
development of mononeuronal innervation as well as for persistent
polyneuronal innervation after prolonged nerve conduction block,
which appears as a consequence of the general competitive interactions
operating during normal development.
Arjen van Ooyen, Netherlands Institute for Brain Research,
Meibergdreef 33, 1105 AZ Amsterdam, The Netherlands.
email: A.van.Ooyen at nih.knaw.nl
phone: +31.20.5665483 fax: +31.20.6961006