Artificial organ a stationary power supply or other stationary resources such as filters or chemical processing units. (Periodic rapid recharging of batteries, refilling of chemicals, and/or cleaning/replacing of filters would exclude a device from being called an artificial organ.) Thus, a dialysis machine, while a very successful and critically important life support device that almost completely replaces the duties of a kidney, is not an artificial organ. Constructing and installing artificial organs, an extremely research-intensive and expensive process initially, may entail many years of ongoing maintenance services not needed by a natural organ.: The use of any artificial organ by humans is
Transneuronal degeneration occurs when a neuron in the central nervous system is damaged and causes the degeneration of a postsynaptic neuron associated with a similar function as the presynaptic neuron. It is often termed "dying forward," and is also referred to as trans-synaptic degeneration. Anterograde degeneration can occur at a late stage of brain injury and result in diaschisis. Retrograde transneuronal degeneration is degeneration caused by loss of 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