Restorative Neurology and Neuroscience - Volume 10, issue 4

Authors: Gómez, Nuria | Cuadras, Jordi | Butí, Miquel | Navarro, Xavier

Article Type: Research Article

Abstract: The present study determines the number and morphology of myelinated fibers that regenerate after resection of the mouse sciatic nerve. In different groups of mice, a resection of 4 or 6 mm of the sciatic nerve was left unrepaired, repaired with silicone or collagen guides or by an autologous nerve graft of the same or smaller calibre. Regeneration was examined, under light microscopy, 3 months after operation and quantified by morphometric analysis of light micrographs of cross-sectional nerve fibers. The results show that, without repair, few nerve fibers reach the distal nerve stump, while tubulization or autografts allowed better regeneration. …Tube repair allowed a comparable degree of regeneration to that of an autograft with 4 mm gaps, but lower with 6 mm gaps. Regeneration was limited with a gap of 6 mm in silicone tubes, but was successful in half the mice with collagen tubes. The size and myelination of regenerated fibers were below normal values in all experimental groups, although they were closer to normal with sciatic autografts than after smaller grafts and tubulization. There were no signs of secondary degeneration in the nerve regenerates within silicone and collagen tubes. © 1996 Elsevier Science Ireland Ltd. All rights reserved Show more

Keywords: Nerve regeneration, Nerve repair, Axon number, Morphometry, Sciatic nerve, Tubulization

DOI: 10.3233/RNN-1996-10401

Citation: Restorative Neurology and Neuroscience, vol. 10, no. 4, pp. 187-196, 1996

Authors: Pizzamiglio, L. | Vallar, G. | Magnotti, L.

Article Type: Research Article

Abstract: In four patients with left visuo-spatial hemineglect and right brain- damage, the therapeutic effects of Transcutaneous Electrical Nervous Stimulation (TENS) of the left neck muscles, associated with a non-specific treatment, and of a specific rehabilitation paradigm were investigated. The two treatments were given for an 8-week period each. TENS had positive effects on hemineglect in two out of four patients, whereas the specific treatment produced a major improvement of the disorder in all four cases. The suggestion is made that an effective treatment of neglect requires a paradigm comprising a range of visuo-spatial exploratory tasks of increasing complexity and a …systematic feedback as to the success of the patients' performance. This is the case of the specific treatment. By contrast a procedure confined to a sensory stimulation, which produces a short-term improvement in the range of minutes, does not have comparable long-term effects. © 1996 Elsevier Science Ireland Ltd. All rights reserved Show more

Keywords: Spatial hemineglect, Rehabilitation, Transcutaneous electrical nervous stimulation, Neck muscle stimulation, Egocentric spatial representation, Sprague effect

DOI: 10.3233/RNN-1996-10402

Citation: Restorative Neurology and Neuroscience, vol. 10, no. 4, pp. 197-203, 1996

Authors: Houle, John D. | Ye, Jian Hui | Kane, Cynthia J.M.

Article Type: Research Article

Abstract: To test whether known growth factors could promote the regenerative reponse of chronically injured neurons, we exposed the injured adult rat spinal cord to insulin-like growth factor 1 (IGF-1), basic fibroblast growth factor (bFGF) or transforming growth factor beta 1 + 2 (TGFβs) 1 month after creation of a hemisection lesion. At 1 week later an autologous peripheral nerve graft was apposed to the rostral cavity wall and 1 month later Nuclear Yellow (NY) was used to retrogradely label neurons that had grown an axon into the graft. Neurons capable of axonal regeneration after a long term (5 weeks) injury …were double labeled with True Blue (TB, provided at the time of hemisection lesion) and NY. Exposure to any of the three growth factors, compared to a PBS-treated control, resulted in a significant increase in the total number of regenerating supraspinal neurons, with the greatest increase after treatment with TGFβs. Treatment with TGFβs or bFGF led to a significant increase in the number of regenerating neurons in 6 out of 7 major regions (excluding the motor cortex) contributing to descending spinal pathways. Treatment with IGF-1 promoted significant regeneration only by reticular formation neurons. These results indicate that exposure to specific growth factors can enhance axonal regeneration by chronically injured neurons, thus overcoming one significant challenge to the repair of long standing structural damage to the spinal cord. © 1996 Elsevier Science Ireland Ltd. All rights reserved Show more

Keywords: Spinal cord injury, Neurotransplantation, Peripheral nerve graft, CNS regeneration, IGF-1, bFGF, TGFβ

DOI: 10.3233/RNN-1996-10403

Citation: Restorative Neurology and Neuroscience, vol. 10, no. 4, pp. 205-215, 1996

Article Type: Research Article

DOI: 10.3233/RNN-1996-10404

Citation: Restorative Neurology and Neuroscience, vol. 10, no. 4, pp. 217-245, 1996