WNT-3, Expressed by Motoneurons, Regulates Terminal Arborization of Neurotrophin-3-Responsive Spinal Sensory Neurons
نویسندگان
چکیده
Sensory axons from dorsal root ganglia neurons are guided to spinal targets by molecules differentially expressed along the dorso-ventral axis of the neural tube. NT-3-responsive muscle afferents project ventrally, cease extending, and branch upon contact with motoneurons (MNs), their synaptic partners. We have identified WNT-3 as a candidate molecule that regulates this process. Wnt-3 is expressed by MNs of the lateral motor column at the time when MNs form synapses with sensory neurons. WNT-3 increases branching and growth cone size while inhibiting axonal extension in NT-3- but not NGF-responsive axons. Ventral spinal cord secretes factors with axonal remodeling activity for NT-3-responsive neurons. This activity is present at limb levels and is blocked by a WNT antagonist. We propose that WNT-3, expressed by MNs, acts as a retrograde signal that controls terminal arborization of muscle afferents.
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عنوان ژورنال:
- Neuron
دوره 35 شماره
صفحات -
تاریخ انتشار 2002