When most people think of the human body, they picture it as a grouping of separate organs and glands, all of which do their own respective jobs to make sure that life is possible. While that is essentially true, every part of the human body is connected to the others on such a deep level that they all work symbiotically. This means that when one aspect of human health goes down, the others are all negatively affected. Essentially, it’s like playing topple the dominos – once you knock one down, they’re usually all going to follow suit.

The brain and the immune system are both incredibly crucial to physical and mental health. While the two may seem to be entirely separate from one another, recent research has discovered that they are far more connected than once thought. This connection between the two is referred to as the brain-immunology axis. But what exactly does that mean, and how do the brain and immune system work together to keep us healthy?

Immunology and the brain

The brain and the immune system actually have a lot in common. They are both highly complex systems that even the brightest of minds have yet to fully understand. They are also able to store memories, learn new information, and communicate to other parts of the body. These striking similarities make the brain and immune system even more intriguing to investigate.

The immune system functions as the body’s defense system against illness and disease, and the brain functions as the captain of the human body ship, so to speak. With this in mind, it seems only natural that the brain would control the immune system as well. But new research is bringing to light ways in which the immune system could also do a little controlling of its own.

Image by Robina Weermeijer on Unsplash: What is the interaction between the brain and the immune system?

How is the immune system connected to the brain?

The brain is connected to the entire body through the nervous system. The nervous system also houses the spinal cord, as well as various vessels and other nerves. It is designed to give the brain and body the ability to communicate and send hormones, chemicals, and neurotransmitters where they need to go.

The signals given from the brain to the body are used to control the functions that keep you alive, such as breathing, digestion, and pain sensations. The immune system and brain are also connected via similar pathways. Both need to relay information to one another, including when the immune system sends off signals to the brain regarding potential threats. However, the brain may have an even more more powerful and important role in the relay of information than once thought.

Does the brain control your immune system?

Although new research is shining a better light on whether the immune system is controlled by the brain much like other bodily systems and organs, it was originally thought that the connection between the two wasn’t all that powerful.

Immunologists of the past thought that studying the brain in correlation to the immune system wasn’t necessary because the immune system isn’t just one thing – it’s made up of many elements such as organs, lymph nodes and fluid, vessels, and cells.

Immune cells move to various areas throughout the body independently, often reacting to certain pathogens without the brain’s input. However, the organs that are involved in immunity, such as the bone marrow, spleen, and thymus, all take direction from the brain.

Recent research has changed how this entire connection is viewed by looking at specific cells such as T-cells. T-cells have receptors that bind to neurotransmitters known as endogenous opiates and norepinephrine. This finding means that not only is the brain able to communicate with the immune system and its cells, the T-cells themselves are created to receive that communication. 

Image by Pawel Czerwinski on Unsplash: Does the brain control the immune system?

What is the interaction between the brain and immune system?

Other interactions between the brain and immune system revolve around hormones. Researchers found that certain hormones produced in the brain were able to suppress inflammation that is caused by the immune response. This led to the discovery that because the brain releases these specific hormones, it can actually control the immune system – in a way that made some researchers believe that the brain itself is in charge of the whole show.

However, the notion that the brain controls the entire system was found to be false. When looking at how the brain and immune system interact with one another, it’s been recently realized that in reality, neither one is calling the shots. They are both in a controlling and receiving position when it comes to their interactions. As is the case with aforementioned T-cells receiving messages, cytokines, which are small immune proteins, direct communication by affecting the brain in various ways.

The brain and the immune system have to work together to function at their best and keep illness and disease at bay. While the immune system is often considered a separate entity, because of its deep connection with the brain, it may be even more influential overall than once thought.

Featured image by Milad Fakurian on Unsplash