Mouse model paves way to study late stages of MS

Researchers have developed a new way to study multiple sclerosis in mice that will enable them to investigate potential treatments for the late stages of the disease.

New drugs are already being tested in the model and it is hoped their approach will bring fresh insights that will speed up the discovery of therapies for the incurable condition.

Immune attack

Multiple sclerosis occurs when the immune system attacks the protective layer around nerve cells, called myelin, which ultimately causes the nerve cells to die.

A mouse model of the disease called EAE has been available for many years and replicates the early stages of the disease, when the immune system is attacking myelin.

Previous tools

The EAE model has been an important tool to help researchers develop the therapies for MS we have available today. These treatments work by trying to dampen down the immune response in the hope of preventing damage to nerves.

Until now, there hasn’t been an effective way to study the later stages of the disease and there are currently no medicines that can repair or replace damaged nerves once this has already occurred.

New approach

Researchers have devised a new way to replicate the loss of myelin and subsequent nerve cell death that occurs during MS using mice.

The procedure involves making a small 2mm hole in the mouse skull and placing a small sponge soaked in a type of detergent at the surface of the brain. The mice are anaesthetised throughout the procedure and are given appropriate pain relief from when they wake up until their surgical wounds heal.

The detergent breaks down the myelin in this small area of the brain, which causes a subset of nerve cells to die. These cells, called inhibitory cells, are the same ones that have been found to be selectively lost in post-mortem samples from MS patient brains.

Moderate procedure

After the procedure, which takes about 20 minutes, the mice recover quickly and don’t require special care. They can feed, run around and do everything as usual. The procedure is classified by the Home Office as mild to moderate.

This is the most realistic mouse model of human MS to date and it could also help us to study other diseases that cause nerve cells to die. We’re hoping it will change the pace of research for neurodegenerative diseases, which has been very slow and rather unsuccessful so far. Professor Anna Williams
Centre for Regenerative Medicine

Studying the brain

Studying diseases that affect the brain is challenging because it is a large and complex organ that involves interactions between numerous cell types. Some things can be studied in the lab using cell cultures and post-mortem samples, but developing new treatments requires understanding how the disease develops in a whole organ and this is currently only possible by using animals.