Emergence of lamina-specific retinal ganglion cell connectivity by axon arbor retraction and synapse elimination.
J Neurosci
; 30(48): 16376-82, 2010 Dec 01.
Article
en En
| MEDLINE
| ID: mdl-21123583
ABSTRACT
Throughout the nervous system, neurons restrict their connections to specific depths or "layers" of their targets to constrain the type and number of synapses they make. Despite the importance of lamina-specific synaptic connectivity, the mechanisms that give rise to this feature in mammals remain poorly understood. Here we examined the cellular events underlying the formation of lamina-specific retinal ganglion cell (RGC) axonal projections to the superior colliculus (SC) of the mouse. By combining a genetically encoded marker of a defined RGC subtype (OFF-αRGCs) with serial immunoelectron microscopy, we resolved the ultrastructure of axon terminals fated for laminar stabilization versus those fated for removal. We found that OFF-αRGCs form synapses across the full depth of the retinorecipient SC before undergoing lamina-specific arbor retraction and synapse elimination to arrive at their mature, restricted pattern of connectivity. Interestingly, we did not observe evidence of axon degeneration or glia-induced synapse engulfment during this process. These findings indicate that lamina-specific visual connections are generated through the selective stabilization of correctly targeted axon arbors and suggest that the decision to maintain or eliminate an axonal projection reflects the molecular compatibility of presynaptic and postsynaptic neurons at a given laminar depth.
Texto completo:
1
Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Células Ganglionares de la Retina
/
Axones
/
Sinapsis
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Membrana Basal
/
Vías Visuales
Tipo de estudio:
Prognostic_studies
Límite:
Animals
Idioma:
En
Revista:
J Neurosci
Año:
2010
Tipo del documento:
Article
País de afiliación:
Estados Unidos