Eliseo Portilla-de Buen1, Hermelinda Salgado-Ceballos2, David González-Tapia3, Caridad Leal-Cortés1, Rodrigo Mondragón-Lozano4, Stephanie Sánchez-Torres5, Laura Álvarez-Mejía5, Omar Fabela-Sánchez6, Néstor I Martínez-Torres7, Myrna M González-Ramírez1, Nallely Vázquez-Hernández1, Ignacio González-Burgos8. 1. Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jal., México. 2. Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México; Proyecto Camina, A.C., Ciudad de México, México. 3. Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jal., México; Universidad Politécnica de la Zona Metropolitana de Guadalajara, Tlajomulco de Zúñiga, Jal., México; Instituto de Ciencias de la Rehabilitación Integral, Guadalajara, Jal., México. 4. Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México; Proyecto Camina, A.C., Ciudad de México, México; CONACyT- Instituto Mexicano del Seguro Social, Ciudad de México, México. 5. Unidad de Investigación Médica en Enfermedades Neurológicas, Hospital de Especialidades, Centro Médico Nacional Siglo XXI, Instituto Mexicano del Seguro Social, Ciudad de México, México; Proyecto Camina, A.C., Ciudad de México, México; Universidad Autónoma Metropolitana Iztapalapa, Ciudad de México, México. 6. Proyecto Camina, A.C., Ciudad de México, México; Universidad Autónoma Metropolitana Iztapalapa, Ciudad de México, México. 7. Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jal., México; Centro Universitario del Norte, Universidad de Guadalajara, Colotlán, Jalisco, México. 8. Centro de Investigación Biomédica de Occidente, Instituto Mexicano del Seguro Social, Guadalajara, Jal., México. Electronic address: igonbur@hotmail.com.
Abstract
BACKGROUND: Spinal cord injury (SCI) is highly incapacitating, and the neurobiological factors involved in an eventual functional recovery remain uncertain. Plastic changes to dendritic spines are closely related with the functional modifications of behavior. AIM OF THE STUDY: To explore the plastic response of dendritic spines in motoneurons after SCI. METHODS: Female rats were assigned to either of three groups: Intact (no manipulations), Sham (T9 laminectomy), and SCI (T9 laminectomy and spinal cord contusion). RESULTS: Motor function according to a BBBscale was progressively recovered from 2 week through 8 week postinjury, reaching a plateau through week 16. Dendritic spine density was greater in SCI vs. control groups, rostral as well as caudal to the lesion, at 8 and 16 weeks postinjury. Thin and stubby/wide spines were more abundant at both locations and time points, whereas mushroom spines predominated at 2 and 4 months in rostral to the lesion. Filopodia and atypical structures resembling dendritic spines were observed. Synaptophysin expression was lower in SCI at the caudal portion at 8 weeks, and was higher at week 16. CONCLUSION: Spinogenesis in spinal motoneurons may be a crucial plastic response to favor spontaneous recovery after SCI.
BACKGROUND:Spinal cord injury (SCI) is highly incapacitating, and the neurobiological factors involved in an eventual functional recovery remain uncertain. Plastic changes to dendritic spines are closely related with the functional modifications of behavior. AIM OF THE STUDY: To explore the plastic response of dendritic spines in motoneurons after SCI. METHODS: Female rats were assigned to either of three groups: Intact (no manipulations), Sham (T9 laminectomy), and SCI (T9 laminectomy and spinal cord contusion). RESULTS: Motor function according to a BBBscale was progressively recovered from 2 week through 8 week postinjury, reaching a plateau through week 16. Dendritic spine density was greater in SCI vs. control groups, rostral as well as caudal to the lesion, at 8 and 16 weeks postinjury. Thin and stubby/wide spines were more abundant at both locations and time points, whereas mushroom spines predominated at 2 and 4 months in rostral to the lesion. Filopodia and atypical structures resembling dendritic spines were observed. Synaptophysin expression was lower in SCI at the caudal portion at 8 weeks, and was higher at week 16. CONCLUSION: Spinogenesis in spinal motoneurons may be a crucial plastic response to favor spontaneous recovery after SCI.