Distinct and developmentally regulated activity-dependent plasticity at descending glutamatergic synapses on flexor and extensor motoneurons.

Constanze Lenschow, Jean-René Cazalets, Sandrine S. Bertrand
Sci Rep. 2016-06-22; 6(1):
DOI: 10.1038/srep28522

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Lenschow C(1), Cazalets JR(1), Bertrand SS(1).

Author information:
(1)INCIA, Université de Bordeaux, CNRS UMR5287, 33076 Bordeaux, France.

Activity-dependent synaptic plasticity (ADSP) is paramount to synaptic processing
and maturation. However, identifying the ADSP capabilities of the numerous
synapses converging onto spinal motoneurons (MNs) remain elusive. Using spinal
cord slices from mice at two developmental stages, 1-4 and 8-12 postnatal days
(P1-P4; P8-P12), we found that high-frequency stimulation of presumed
reticulospinal neuron axons in the ventrolateral funiculus (VLF) induced either
an NMDA receptor-dependent-long-term depression (LTD), a short-term depression
(STD) or no synaptic modulation in limb MNs. Our study shows that P1-P4 cervical
MNs expressed the same plasticity profiles as P8-P12 lumbar MNs rather than P1-P4
lumbar MNs indicating that ADSP expression at VLF-MN synapses is linked to the
rostrocaudal development of spinal motor circuitry. Interestingly, we observed
that the ADSP expressed at VLF-MN was related to the functional flexor or
extensor MN subtype. Moreover, heterosynaptic plasticity was triggered in MNs by
VLF axon tetanisation at neighbouring synapses not directly involved in the
plasticity induction. ADSP at VLF-MN synapses specify differential integrative
synaptic processing by flexor and extensor MNs and could contribute to the
maturation of spinal motor circuits and developmental acquisition of
weight-bearing locomotion.

DOI: 10.1038/srep28522
PMCID: PMC4916427
PMID: 27329279 [Indexed for MEDLINE]

Auteurs Bordeaux Neurocampus