Understanding the role of microglia is helping scientists work toward improved treatments for neurodegenerative diseases.
Studies show it is possible that these fascinating and hard-working cells may be linked to conditions such as dementia.
What are microglia?
Immune cells are important to our bodies, and microglia work hard to make sure your brain is protected and able to function, even changing shape to suit the required function.
Microglia only make up a small number of the cells in your brain, but their role is crucial – and what busy little cells they are.
Multitasking microglia
It turns out, some of their roles throughout your lifetime include:
- Canteen duty
Studies have shown these cells are integral to brain maturation, regulating cholesterol for neuron development in the brain.
- Brain gardener
Microglia quite fancy a bit of synaptic snipping and shaping to make sure your brain stays in peak working order.
- Clean-up crew
These cells also get rid of waste and debris that might interfere with brain activity, including but not limited to plaque deposits related to Alzheimer’s.
- Repair and maintenance
Microglia make sure to maintain myelin, the insulating membrane for nerve cells allowing electrical impulses to travel smoothly.
- Executive decisions
In recent years scientists have explored the role microglia plays in neurogenesis, the generation of new neurons in the brain.
- Defence forces
Microglia will take on viruses and bacteria, and help identify and address injury as part of the immune response that protects the central nervous system.
Unfortunately, it would seem microglia may be a little too enthusiastic on the job.
Where it starts to go wrong
When working to protect your brain, microglia can release pro-inflammatory cytokines as part of the immune response.
Unfortunately, once the threat has passed, sometimes microglia continue creating the cytokines, inflaming your brain.
Therein lies the crux of the issue: having these cells stuck on ‘active’ can result in neuroinflammation and, no, that’s not a good thing.
According to studies, some neurological diseases are highly correlated with neuroinflammation and cytokine unregulation.
Alzheimer’s disease, among other forms of dementia, and multiple sclerosis, for example.
In summary, rather than performing in a supportive or protective role, the ongoing active state of the microglia is unfortunately having a detrimental effect on your brain.
Figuring out ways to stop this activation could be a key component of hopefully slowing the progress of certain brain diseases.
For example, by growing and imaging the microglia, a group of researchers were able to essentially see what happens during the process of activation.
The elderly and microglia
Microglia also feels the impact of ageing: amid the never-ending work, microglia appear somewhat trigger-happy as time goes by, becoming sensitised.
In Alzheimer patients, microglia can start over-pruning the synapses – and there are the complicated relationships with plaque and protein associated with Alzheimer’s.
Among the identifiers of Alzheimer’s are plaque formations made of protein clumps in the brain, while another protein forms what is referred to as tangles, both believed to disrupt messaging.
Pinpointing exactly how microglial activity and the different types of plaque relate during the development of Alzheimer’s is clearly an area for future and ongoing study.
Further identifying how microglia manages to help – and it turns out, simultaneously not help – protect the brain is an integral step forward in refining future treatment possibilities.
On top of this, genetics plays a part in the development of neurodegenerative disorders, a link that scientists are still exploring in relation to microglia.
Microglia and the future
With Alzheimer’s set to have a huge global impact in coming decades, research in Australia and around the world in recent years continues to expand knowledge around microglia.
Over time, the goal is that understanding these elements will transition into viable therapies to help slow the progress of dementia.
Due to the diverse nature of microglia’s impact in the brain, scientists are also looking at an array of chronic conditions where microglia may have a role.
Could fibromyalgia, Parkinson’s disease and long COVID simply be the tip of the iceberg? Only time and research can offer the answers.
At this point, understanding this busy little bee of a cell by defining the multifaceted role of microglia in the brain – and relation to cognitive function – is the best step forward.
Are you familiar with the roles of microglia? Do you think you can use this knowledge to your advantage? Let us know in the comments section below.
