Research on Traumatic Paraplegia

Previous research begun in 1980, and done on rats and monkeys, showed that muscles surgically disconnected from the lower motoneurons responded to the stimuli of the upper motoneurons.

Recently three human beings have been operated on. The first who had undergone guillotine severance of the cord by dislocation of T8 is now able to walk with tripod sticks. The other two are still too recent to evaluate function.

Research was carried out on animals to see whether it is the motor end-plate which changes its receptors from cholinergic into glutamatergic, or if it is the upper motoneuron which changes its neurotransmitter from glutamate to acetylcholine. A graft was placed from the severed lateral or posterior white matter (rubrospinal and cortico spinal tracts) to the muscular nerve of the obliquus muscle in rats.

Functional reinnervation of the muscle was shown by EMG and immunostaining. Genes codifying for receptors, as well as the neurotransmitter, were searched out. Curare paralyzed all the other muscles but not the operated one, whereas inhibitor for glutamate paralyszed the operated side. Immunoblot test showed that the operated muscle contained vesicular glutamate transporter-1 (VGluT-1), whereas the control muscle still contained ChAT and VAChT. Direct muscular innervation by the upper motoneuron makes the muscles function, probably due to change of the receptors of the motor end-plate.