title: Multiple Retinal Axons Converge onto Relay Cells in the Adult Mouse Thalamus.
abstract: Activity-dependent refinement of neural circuits is a fundamental principle of neural development. This process has been well studied at retinogeniculate synapses-synapses that form between retinal ganglion cells (RGCs) and relay cells within the dorsal lateral geniculate nucleus. Physiological studies suggest that shortly after birth, inputs from ∼20 RGCs converge onto relay cells. Subsequently, all but just one to two of these inputs are eliminated. Despite widespread acceptance, this notion is at odds with ultrastructural studies showing numerous retinal terminals clustering onto relay cell dendrites in the adult. Here, we explored this discrepancy using brainbow AAVs and serial block face scanning electron microscopy (SBFSEM). Results with both approaches demonstrate that terminals from numerous RGCs cluster onto relay cell dendrites, challenging the notion that only one to two RGCs innervate each relay cell. These findings force us to re-evaluate our understanding of subcortical visual circuitry.
authors: Virginia Tech Carilion Research Institute, Roanoke, VA 24016, USA.
authors: Sarah
authors: S
authors: Hammer
authors: Virginia Tech Carilion Research Institute, Roanoke, VA 24016, USA; Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA.
authors: Aboozar
authors: A
authors: Monavarfeshani
authors: Virginia Tech Carilion Research Institute, Roanoke, VA 24016, USA.
authors: Tyler
authors: T
authors: Lemon
authors: Virginia Tech Carilion Research Institute, Roanoke, VA 24016, USA.
authors: Jianmin
authors: J
authors: Su
authors: Virginia Tech Carilion Research Institute, Roanoke, VA 24016, USA; Department of Biological Sciences, Virginia Tech, Blacksburg, VA 24061, USA; Department of Pediatrics, Virginia Tech Carilion School of Medicine, Roanoke, VA 24016, USA; Faculty of Health Sciences, Virginia Tech, Blacksburg, VA 24061, USA. Electronic address: mafox1@vtc.vt.edu.
authors: Michael Andrew
authors: MA
authors: Fox
mesh_terms: D000818:Animals; D001369:Axons / Q000502:physiology / Q000648:ultrastructure*; D008810:Mice, Inbred C57BL; D012165:Retinal Ganglion Cells / Q000502:physiology / Q000648:ultrastructure; D013788:Thalamus / Q000166:cytology*; D014795:Visual Pathways / Q000166:cytology