I’m back again today with another topic I want to talk about! I’ve actually touched on the topic of dementia before in a previous post, but as I was reviewing it I realised that I hadn’t discussed whether a cure would be a possibility, which is something that everybody seems to wondering and hoping. I would like to use this post to review current research on dementia and reflect on other ways that scientists are hopeful the condition could be cured. I will be discussing: the development of dementia, trials for a new dementia drug, strobe light therapy, gene therapy, a dementia vaccine and stem cells. Now let’s jump straight into it. Make sure you read the post I wrote earlier for a good background before you delve into this one.
Development of Dementia
Dementia is essentially an umbrella term for many different conditions, but for the purpose of this post I will be focussing on the most common form of dementia, Alzheimer’s disease.
An adult brain contains about 100 billion nerve cells which each contain many different branches, creating more than 100 trillion connections. Signals pass through these connections to form the basis of memories, thoughts, and feelings and it is these neurones that are destroyed in Alzheimer’s disease. The loss of brain cells causes the brain to shrink causing plaques of protein to gradually form in the brain. The plaques are thought to be responsible for accelerating dementia by causing more brain cells to be destroyed. Scientists aren’t exactly sure what causes the cell death in the first place, but it is agreed that the formation of plaques could play a huge role in this.
The plaques form when protein pieces called beta-amyloid clump together. The small clumps of this protein can block synapses and prevent impulses from passing. The spread of these plaques throughout the brain causes the progression of Alzheimer’s.
Dementia Drug Trials
Earlier this year there was some news on trials on a drug named Solanezumab which would destroy the plaques that build up in the brain of patients with Alzheimer’s. The initial results published showed that taking the drug had cut the rate of the disease’s progression by about 34%. Data also showed that patients who took the drug for the longest period saw the best results in terms of cognitive ability. However, the latest trial conducted about a month ago ended in failure after showing that there is no differences in cognitive decline of those taking the drug compared to those given a placebo. Although the trials for this particular drug failed, it could be possible to develop another drug that has the same principle intended effect.
Strobe Light Therapy
A team of researchers have found that flashing a strobe light into rodents’ eyes encouraged cells to break down the harmful beta-amyloid proteins. The mice used in the study had been genetically programmed to develop Alzheimer’s disease, the disease had not progressed enough for them to display the symptoms of the disease or form plaques in their brains. However, if the number of beta amyloid proteins is reduced it will prevent the plaques from forming and prevent cell death.
The treatment works by setting the light to flicker at a certain frequency, inducing brain waves called gamma oscillations. The gamma waves suppress the production of beta amyloid in the brain but also increase the activity of cells called microglia, which engulf the beta amyloid cells. The results from the mice showed that beta amyloid levels were cut by nearly a half. The results also showed that in mice where plaques had already developed the treatment had to be given for several days for the number plaques to remain low. The researchers say that the approach should now be tested in humans. If the human trials for this are successful, it would be incredible as this is a non-invasive and essentially easy treatment to deliver.
Gene therapy is a fairly new area of research which could be used to treat a multitude of conditions. The new gene editing tool, CRISPR is a revolutionary medical adavnacement making the process of editing or disabling certain genes much easier. In 2015, a little girl was treated with gene-edited immune cells that eliminated all signs of the leukaemia that was killing her. Over the past few years, a type of gene therapy in which healthy genes are injected into the eye to repair mutations has shown to have successful results in treating congenital and degenerative blindness. In dementia, gene therapy could stop brain cells dying, or possibly replace them.
Some gene therapy trials have been carried out on mice. The treatment used a harmless modified virus to carry the gene, PGC1-alpha, into parts of the brain most affected by Alzheimer’s. The gene is believed to block formation of beta-amyloid. The mice were treated at the early stages of Alzheimer’s disease, when they still had not developed amyloid plaques. After four months, the team found that mice who received the gene had very few amyloid plaques, compared with the untreated mice, who had multiple plaques in their brain. The treated mice also performed as well as healthy mice in memory tasks. They also discovered that there was no loss of brain cells in mice who received the gene treatment.
So far there has been no evidence to explain why the beta-amyloid plaques form in the brain. It has however, been suggested that it could be the brain’s defence against invading microbes. In order to test this, a research group injected bacteria into the brains of mice and noticed that plaques developed straight away, trapping these microbes. If these pathogens are vaccinated against, the immune system could attack them without the need to form beta-amyloid plaques.
There have also been suggestions of developing a vaccine of antibodies which would stimulate the immune system to recognise the abnormal beta-amyloid plaques. The immune system would then attack these plaques and break them down, slowing the progression of Alzheimer’s disease.
Researchers hope that, stem cells could be used to develop new brain cells to replace the cells that are damaged by dementia. A breakthrough that has been the very successful is the transplantation of human brain stem cells into the brains of very old rats. The transplanted human stem cells produced new nerve cells and this was found to significantly improve the cognitive function of the rats.
Overall, as you can see there’s quite a few different areas being explored to search for a possible cure for dementia. It’s hard to say which would be the leading area of research in this field, but we can definitely agree that all these interventions do give us some hope in the possibility of halting the progression or even reversing the effects of dementia. We are now living in a society where people are living much longer lives, making the idea of dementia a much more probable to a greater scale of people. It is therefore worth investing some time and money to investigate effective treatments as dementia could be as common as 1/3 of the population suffering from it in just a few decades.