Retrograde transneuronal degeneration

Retrograde transneuronal degeneration is trophic support from the target. It occurs in presynaptic cells that are sending inputs to injured postsynaptic cells.  It is often termed "dying backward."  This type of degeneration can be seen in Amyotrophic lateral sclerosis.  Loss of Betz cells is a variable effect of this disease but the loss of these cells in this disease demonstrates the “dying-back” (axonopathy) due to the changes in upper motor neurons.