Geneeskundige Stichting Koningin Elisabeth ... - GSKE - FMRE

Spinal Cord Traumatic Lesion
Martin, D. 1 , Maquet, V. 2 , Scholtes, F. 1 , Schoenen, J. 3 and Moonen, G. 1
1 Centre de Neurobiologie Cellulaire et Moléculaire, Université de Liège, Belgique
2 Service de chimie des matériaux, Université de Liège
3 Centre de Neurobiologie Cellulaire et Moléculaire, Service de Neuroanatomie Université de
Liège, Belgique
The great diversity of the spinal cord lesions observed in human beings does not find his
correspondence in the experimental models intended to study them. Some models, such as
medullary section, kinetic compressions with the traditionnal technique of the released weight
or the photochemical lesions aimed to study particular aspects of the lesion and regeneration
of the injured spinal cord, are imitating only one particular aspect of the human situation. That’s
the reason why we described first another model of acute compression of spinal cord, who uses
a inflatable small balloon introduced into space under-dural in the adult rat and which, contrary
to the models classically used, allows to induce a medullary contusion in a closed space. The
modulation of the physical parameters of compression (volume of inflation, duration of compression)
can modify in a reproducible way the importance of the medullary contusion and can
be correlated with behavioral deteriorations which result from it. The detailed study of the evolution
of the lesion during the first four weeks following the lesion enabled us to show the massive
but transitory regeneration of axons originating from telencephalic regions in the injured
CNS. It is associated with the invasion of the lesion by a heterogeneous cellular population
made up of macrophages, endothelial cells and especially
Schwann cells which are organized in a screen directed in the large axis of the spinal cord.
Moreover, we developed various techniques of repair of the damaged spinal cord. In particular,
we used various cellular types for grafting with the aim to modify the injured site and to bring
elements favorable to its rebuilding. As we showed, there is an important axonal regeneration in
the injured CNS but it is only transitory and disappear gradually. In our approach of transplantation,
we systematically used cells coming from adult syngenic animals in order to place us from
the clinical point of view for autograft Schwann cells constitute a particularly interesting cellular
stock since they sustain a effective axonal regenetion in the PNS. In the spinal cord lesion induced
in our model using the inflatable small balloon, the grafted Schwann cells are quickly integrated.
They limit post-traumatic cavitation and the gliosis. They favor a massive axonal regrowth,
but the immunohistochimic characterization of fibres demonstrate a local origin starting from the
adjacent spinal ganglia with the lesion rather than a telencephalic source. By allowing the axonal
growth within the injured CNS, the grafted Schwann cells “peripheralize” the injured spinal cord.
In order to favor the fast elimination of the myelin debris which accumulate in the lesion,
we carried out transplantations of peritoneal macrophages. They are able to be integrated in
the spinal cord and to reduce the cystic cavitation and do not induce an important gliosis. To
a lesser degree than Schwann cells, they are able to support the axonal regrowth coming from
spinal ganglia. If they contribute, by reducing the myelin debris accumulated in the lesion, “ to
decentralize “ the CNS, they support also the migration of Schwann cells from the adjacent dorsal
roots and by ths way, stimulate te axonal regrowth from spinal ganglia.
137