Volume EM Reconstruction of Spinal Cord Reveals Wiring Specificity in Speed-Related Motor Circuits.
Cell Rep
; 23(10): 2942-2954, 2018 06 05.
Article
en En
| MEDLINE
| ID: mdl-29874581
ABSTRACT
Spinal interneurons coordinate the activity of motoneurons to generate the spatiotemporal patterns of muscle contractions required for vertebrate locomotion. It is controversial to what degree the orderly, gradual recruitment of motoneurons is determined by biophysical differences among them rather than by specific connections from presynaptic interneurons to subsets of motoneurons. To answer this question, we mapped all connections from two types of interneurons onto all motoneurons in a larval zebrafish spinal cord hemisegment, using serial block-face electron microscopy (SBEM). We found specific synaptic connectivity from dorsal but not from ventral excitatory ipsilateral interneurons, with large motoneurons, active only when strong force is required, receiving specific inputs from dorsally located interneurons, active only during fast swims. By contrast, the connectivity between inhibitory commissural interneurons and motoneurons lacks any discernible pattern. The wiring pattern is consistent with a recruitment mechanism that depends to a considerable extent on specific connectivity.
Palabras clave
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Médula Espinal
/
Procesamiento de Imagen Asistido por Computador
/
Microscopía Electrónica
Límite:
Animals
Idioma:
En
Revista:
Cell Rep
Año:
2018
Tipo del documento:
Article