Motor deprivation in healthy animal model: a Galilean approach for movement limiting neurological diseases

Several neurological diseases are associated with or are the cause of movement impairments; among them spinal muscular atrophy, spinal cord injury, multiple sclerosis are examples with analogous effects on anti-gravity muscles. Since life support will increases the survival expectations of these patients, they will be likely exposed to the effects of the prolonged motor deprivation. We studied the lack of movement in a healthy wild type animal using the hind limb unloading model (HU). Four month old mice were suspended from the tail, HU group, for 14 days, whereas the controls (CTR) were left free to move in a similar cage. From our in vitro analysis we determined that Neural Stem Cells (NSCs) derived from the sub ventricular zone of HU mice show a lower proliferation capability compared to CTR mice with a doubling time that is almost 4 times that observed in the CTR. These results are in agreement with a cytofluorimetric analysis of the cell cycle. In addition, in HU derived NSCs, the differentiation is altered, with a significant reduction of the number of β-Tubulin III positive cells and a co-expression of Glial Fibrillary Acidic Protein, that suggests an incomplete differentiation/maturation of the NSCs which, most likely, do not reach mature neuronal electrical membrane properties. Hu derived NSCs have a lower metabolic activity. This research will help to confirm the role of exercise as a useful treatment for many neurological and neurodegenerative diseases.