The brain’s immune system influences our thoughts and moods

It seems our personality is less an arbitrarily complex system and more a consequence of how the brain’s immune system works.

The brain has its own immune system

The immune system isn’t a single part system. Different parts of our body have different immune systems and they all meet in the lymphatic system.

The lymphatic system acts as a sewer system that takes over the waste each immune system throws after dealing with whatever is wrong with the organ they’re protecting. The eyes, for example, have their immune system. And so, does the brain.

The brain’s immune system is made of cells called microglia, which are located throughout the brain and spinal cord. The most surprising thing about those cells is their histrionic behavior. They’re like actors playing roles, according to the specific stage direction they were given.

The duality of microglia

Microglia can be brain repairers, life supporters, nurses, fighters, and also killers. When they are not needed, they are inanimate. But, depending on the direction they are given, they activate and start spelling different chemicals, according to the script they are given.

Anatomy of a microglial cell.

Microglia have an important role in scenarios such as Alzheimer’s, Parkinson’s, or multiple sclerosis. But they don’t just help reduces the inflammation caused by those illnesses. They also betray their nature and become the enemy, by worsening the inflammation.

Microglia are the neurological version of Jekyll and Hyde

When they are playing the role of M2, microglia repair neurons, keep them alive, and even grow them. They fight inflammation and protect the brain from damage. But when they go into M1 state, they become vicious assassins that damage the brain functions.

The most common damages microglia generate are mood changes and impaired cognition. Depression is a result of this neural process. This is how every other inflammation in the human body, such as hepatitis, for instance, can generate symptoms of depression.

Depression, cognition, and microglia

Since everything that is going on in the body goes through brain reception and command, every inflammation will alert microglia. And what microglia do in response, is to enhance the inflammation by playing the M2 role. It starts damaging neurons and, even more so, to inhibit their production.

This is why the hippocampi of patients with Alzheimer’s reveal significant atrophy. And microglia have a leading part in this awful scenario. The hippocampus (and we have two of those, one in each hemisphere of the brain) is the memory center.

Depression and moods are interdependent. Alzheimer’s and cognition as well. And both of those diseases are linked to microglia.

Personality and microglia

By looking at things at a smaller scale where there is no disease, only healthy human bodies, can you see the influence microglia has on our daily cognition and moodiness? Our personality is dependent on it.

So, maybe, you would rethink your lifestyle. Maybe you will show a higher degree of consideration for your diet, sleep, and exercise. Everything you do gets through your microglia. Keeping your microglia asleep might with help your personality.