Transynaptic Retrograde Degeneration

More than half a century ago, the phenomenon of transneuronal retrograde degeneration was shown convincingly at two levels of the monkey visual system: 1) within the inner nuclear layer of the retina, where cysts form after ganglion cell axon transection and 2) in the retinal ganglion cell layer, where neurons are lost after occipital lobe removal. The phenomenon has been rediscovered in humans with the advent of optical coherence tomography (OCT). In patients with an optic neuropathy, a ring of microcysts often appears in the macula. In patients with occipital lobe damage, the ganglion cell complex shows homonymous thinning, corresponding to the pattern of visual field loss.vpdiseasesoftheretrochiasmalvisualpathway