What’s the point of keeping a nerve cell alive without an axon?

We put this question to Dr Michael Coleman:

Michael - That's a very good question. We cut axons in a culture dish because that's a very well defined beginning of the degeneration period, and it gives us good control over when that degeneration starts. But there's very good evidence now that a similar mechanism of degeneration takes place in several neurodegenerative disorders; motor neuron disease; glaucoma, where pressure in the eye actually causes the axons to degenerate, and probably an Alzheimer's disease too. So, we're using the cutting model as a model for what's happening in the neurodegenerative disorders. A good analogy, going back again to the traffic holdup, it would be the difference between actually closing a motorway, so you totally block the motorway - that will be the cut - and restricting the traffic for example to one lane or some speed limits. That the type of holdup is quite different, but the particular traffic that's affected by that is actually going to be quite similar.