title: Treadmill training induces plasticity in spinal motoneurons and sciatic nerve after sensorimotor restriction during early postnatal period: new insights into the clinical approach for children with cerebral palsy.
abstract: The aim of the present study was to investigate whether locomotor stimulation training could have beneficial effects on the morphometric alterations of spinal cord and sciatic nerve consequent to sensorimotor restriction (SR). Male Wistar rats were exposed to SR from postnatal day 2 (P2) to P28. Control and experimental rats underwent locomotor stimulation training in a treadmill for three weeks (from P31 to P52). The cross-sectional area (CSA) of spinal motoneurons innervating hind limb muscles was determined. Both fiber and axonal CSA of myelinated fibers were also assessed. The growth-related increase in CSA of motoneurons in the SR group was less than controls. After SR, the mean motoneuron soma size was reduced with an increase in the proportion of motoneurons with a soma size of between 0 and 800 μm(2). The changes in soma size of motoneurons were accompanied by a reduction in the mean fiber and axon CSA of sciatic nerve. The soma size of motoneurons was reestablished at the end of the training period reaching controls level. Our results suggest that SR during early postnatal life retards the growth-related increase in the cell body size of motoneurons in spinal cord and the development of sciatic nerve. Additionally, three weeks of locomotor stimulation using a treadmill seems to have a beneficial effect on motoneurons' soma size.
authors.affiliation: Programa de Pós-Graduação em Neurociências, Instituto de Ciências Básicas da Saúde, Universidade Federal do Rio Grande do Sul, RS, Brazil. fstigger@yahoo.com.br
authors.forename: Felipe
authors.initials: F
authors.lastname: Stigger
authors.forename: Patrícia S
authors.initials: PS
authors.lastname: do Nascimento
authors.forename: Márcio F
authors.initials: MF
authors.lastname: Dutra
authors.forename: Gabriela K
authors.initials: GK
authors.lastname: Couto
authors.forename: Jocemar
authors.initials: J
authors.lastname: Ilha
authors.forename: Matilde
authors.initials: M
authors.lastname: Achaval
authors.forename: Simone
authors.initials: S
authors.lastname: Marcuzzo
mesh_terms: D000818:Animals; D002547:Cerebral Palsy / Q000473:pathology / Q000503:physiopathology* / Q000628:therapy; D002648:Child; D005260:Female; D006801:Humans; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D009046:Motor Neurons / Q000166:cytology / Q000502:physiology*; D018482:Muscle, Skeletal / Q000502:physiology; D009473:Neuronal Plasticity / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D011247:Pregnancy; D011897:Random Allocation; D051381:Rats; D017208:Rats, Wistar; D012584:Sciatic Nerve / Q000033:anatomy & histology / Q000502:physiology*; D013116:Spinal Cord / Q000166:cytology* / Q000502:physiology