Motor neurones are the longest cells in the human body and can reach up to 1 metre in length. This causes a few transport problems for the cell as it must use a large amount of energy to power the transport of all kinds of molecules needed in the far reaches of the synapse.
The neurone runs a highway of sorts carrying its molecular passengers to the synapse. Dr Anna King and co-workers at the Menzies Research Institute in Hobart have found that in MND the long axons of the motor neurones have an unusual amount of blockages or traffic jams. The long axon of the motor neurone bulges and swells and the passage of important molecules is blocked. Eventually these blockages could be detrimental to the neurones.
Interestingly, the researchers found that it is the influence of cells in close proximity to the motor neurone that determine if there will be a blockage or not. The next exciting step will be to identify how the neighbouring cells cause the traffic jam.
Source: International MND research update – June 2009, Dr Justin Yerbury for MNDRIA