Segmentations of 3D electron microscopy image volume from an albino mouse dorsal lateral geniculate nucleus

In albino mice and EphB1 knock out mice, mistargeted retinal ganglion cell
(RGC) axons form dense islands of axon terminals in the dorsal lateral
geniculate nuclei (dLGN). The formation of these islands of retinal input
depends on developmental patterns of spontaneous retinal activity. We
reconstructed the microcircuitry of the activity-dependent islands and
found that the boundaries of the island represent a remarkably strong
segregation within retinogeniculate connectivity. We conclude that, when
sets of retinal input are established in the wrong part of the dLGN, the
developing circuitry responds by forming a synaptically isolated
subcircuit within the otherwise fully connected network. The fact that
there is a developmental starting condition that can induce a synaptically
segregated microcircuit has important implications for our understanding
of the organization of visual circuits and for our understanding of the
implementation of activity-dependent development.