US group to fund Australian spinal cord map

Researchers at the Spinal Injuries Research Centre at the Prince of Wales Medical Research Institute have received AUD$200,000 from the Christopher Reeve Paralysis Foundation to produce a three-dimensional map of the rat spinal cord that will be made publicly available on the internet.

"There is no comprehensive study or atlas of the spinal cord, rat or human," said Prof George Paxinos, who is conducting the project along with colleague Dr Yuri Koutcherov.

"Many focused studies have been done on the spinal cord, which look at a particular muscle group and its connections to the spinal cord, but no thorough study on the structure of the spinal cord -- global studies like this are difficult to do."

The rat is currently the principal animal for spinal cord injury research -- Paxinos said the rat spinal cord and brain stem are 95 per cent or more homologous to human.

Although not a spinal cord researcher, Paxinos has produced atlases of human, monkey, rat and mouse brains. In fact, The Rat Brain in Stereotaxic Coordinates, a rat brain atlas constructed by Paxinos and C Watson in 1986 is the most cited Australian publication according to Thomson ISI.

"What we need is one well-sectioned spinal cord of the rat in the transverse plane," Paxinos said of the process used to create the atlas. "We will need to section a lot of spinal cords to get additional data, but we will be best served to have one specimen with which to make the atlas."

The researchers will initially section the spinal cord at about 150 levels and use basic histochemical stains, such as Nissl stains, which reveal neurons and glial cells.

"Additional levels will then be sectioned, another few thousand or so, to demonstrate various other stains for specific neurotransmitters, neurotransmitter receptors, proteins, etc," explained Paxinos. "The more windows we have the better."

Paxinos said the atlas will not try to replicate work that has already been done, such as the mapping of efferent and afferent connections to the spinal cord from muscles, but will take information from the literature and add it to the atlas.

"We will then take a preliminary map to experts in different areas for them to inspect and/or improve our delineations," he said.

The atlas will be designed in a way that other maps can be overlayed on it, bringing a synergy to research in spinal cord mapping.

"Our reson detra is that this will cover all aspects of the spinal cord," Paxinos said.