The organisation of spinal projecting brainstem neurons in an animal modelof muscular dystrophy - A retrograde tracing study on mdx mutant mice

Previous studies we performed on the mdx mouse demonstrated marked central nervous system alterations in this model of human Duchenne muscular dystrop hy, such as reduction in number and pathological changes of cortico-spinal neurons. Prompted by these findings we extended the survey of the mdx brain to the major brainstem-descending pathways: the rubro-, vestibulo-, reticu lo-, and raphe-spinal projections. Horseradish peroxidase microinjections w ere performed in the cervical spinal cord of mdx and control mice. The rubr o-spinal neurons were found to be significantly reduced in mutants compared to controls. The vestibule-spinal, reticulo-spinal. and raphe-spinal cell populations, though less numerous in mdx than in control mice, were instead substantially spared. Our data further unveil the selective nature of mdx brain damage indicating a marked and selective involvement of the highest c enters for motor control. (C) 2001 Elsevier Science B.V. All rights reserve d.