How can Brain Flu Affect your Central Nervous System?

How can Brain Flu Affect your Central Nervous System?

Flu brain is real and everyone is trying hard to avoid it this season. You may notice people side-eyeing you as you a cough or sneeze in public.

You already know about the symptoms of flu brain as well. But have you ever wondered what these viruses can do once they get inside your body, specifically the brain?

What is Flu Brain?

The Immune Response

For understanding how the virus affects your brain, it is necessary for you to develop an understanding of how the immune system works once it detects a pathogen.

As the virus infiltrates your body, the immune system becomes activated. This system works like a defense mechanism to avoid the virus from getting out of control and causing serious damage.

The invasion: 

In the beginning, the virus attacks the host cells so as to remain hidden from the immune system as it replicates. This increases its chances of survival. Despite this survival mechanism, the immune system in your body has a technique to detect if a cell is behaving normally or not.

flu brain

A group of molecules known as class 1 major histocompatibility complex (MHC class1) naturally display its pieces from within the cell to its surface. The cells which are potentially infected with a virus will cause these MHC class 1 proteins to emerge on the cell surface. These pieces will carry fragments of the virus along with them.

Hence, a cascade of events will initiate in order to destroy the virus and secure the body

In addition to the exposure of the virus onto the cell surface, the host cells begin releasing interferons that cause the surrounding cells to raise their MHC class 1 presentation. This helps the body draw attention towards the virus.

Recognition and Defense:

The immune system consists of different types of white blood cells wandering in your body in search of foreign invaders. Some of these white blood cells include T cells, monocytes, macrophages, mast cells, and Natural Killer cells.

The natural killer cells are responsible for finding virus-infected cells that display a lower amount of MHC class 1 proteins. In such cells, the natural killer cells induce cell death. Cytotoxic cells, a particular type of T cells, are capable of recognizing the infected cells and releasing cytotoxic factors to kill them immediately.

RELATED: The Mind Diet: A Guide to a Sharper Brain

Cytotoxic T cells can also manufacture and release cytokines. Cytokines, being pro-inflammatory, lead to the activation and the organization of an immune response directed towards a viral infection.

This immune response is initiated as the cytokines bind to specific cell receptors, giving rise to intracellular signaling. The gene expression gets altered and the cell death occurs.

Immune Responses and the Role of Brain

The symptoms of flu or a cold are actually the physical manifestations that your immune system is responding against a viral infection. The release of cytokines in the body is indicated by other symptoms such as fever, fatigue, decreased appetite, and a loss of mood, motivation, and concentration.


Neurotransmitters tend to play an important role in flu brain. An immune system response occurring in the central nervous system causes the production of a number of precursors and neurotransmitters such as dopamine, choline, noradrenaline, serotonin, and glutamate.

flu brain

The release of cytokines activates a pathway causing a depletion of precursors of certain neurotransmitters. This causes a decrease in the synthesis, release, and reuptake of these neurotransmitters.

A fall in the concentration of serotonin and dopamine can affect the memory and learning. It can also decrease the “feel good” sensations giving rise to a saddened state.

A decrease in noradrenaline, on the other hand, can slow down the reaction time. Reduced levels of choline can directly affect the ability of your body to retain new information whereas decreased glutamate damages muscle.

A decrease in neurotransmitters can also affect the neural circuits in certain areas of the brain. The neural circuits particularly present in the amygdala, anterior cingulate cortex, basal ganglia, and hippocampus are particularly damaged. All of these regions are primarily associated with arousal, motivation, alarm, anxiety, motor activity, and memory.


Hypothalamus is a region that controls hunger, thirst, body temperature, and other autonomic functions. Within this region, the release of cytokines causes alterations in the homeostatic state of the body in order to get rid of the virus. This causes an increase in temperature and sleep and a reduction in appetite.

A research has concluded that the cerebral spinal fluid can wash away the proteins that accumulate in the spaces between the brain cells. This is an important process as the body is fighting infection and is trying to deal with the increased amount of protein that needs immediate removal from the neuronal spaces. All this debris can otherwise generate a feeling of brain fog.

RELATED: Brain cells that explain the anxiety- Latest Research Findings


The pro-inflammatory immune response going on in your body to fight flu brain can affect mood and cognition. It can decrease the mental processing and learning, eventually leading to a depressed state. Just like sleep deprivation or alcohol, seasonal diseases can impair cognition via dampening reaction times and the information storage capacity.

flu brain

A lot of studies have indicated inflammation as a key factor linking the neurological, immune, and psychological systems together. This association between the three different systems is what gives rise to cognitive deficits often observed during a seasonal disease.

For example, a study carried out in 2015 included 25 students who had to take simulated driving tests in the form of two different sessions. During the first session, 15 out of 25 students were suffering from head cold and had fully recovered during the second session.

The results recorded in the study revealed that the reaction had been impaired, particularly for the unexpected events, even though there was no impairment seen in the basic driving skills.

How to Prevent Flu Brain

Unfortunately, there is not much you can do to prevent flu brain as it is a sign that your body is combatting against a particular virus.  However, what you can do is to follow some simple steps to help your body fight infection and reduce the symptoms of this combat.

  1. Think Positive

Whatever you do, do not underestimate the power of optimistic thinking. Studies have indicated that a positive approach can markedly reduce the intensity of the symptoms. In some cases, it can even provide protection against the seasonal illnesses as well.

  1. Sleep Well

Sleep deprivation is the last thing your body needs, especially when you are fighting a flu attack. Sleep allows your body to focus all of its energy on combatting the virus. It also permits your body to wash away all the debris stuck between the cells of your brain.

  1. Go for Caffeine

A study conducted in 2014 has indicated the potential benefits of coffee along with ibuprofen, an anti-inflammatory medicine. In this study, the participants were provided with either 100 mg of caffeine or 200 mg of ibuprofen. Some of them were provided with both these substances together.

flu brain

The results were recorded and the results were matched with the placebo group.

Both caffeine and ibuprofen were found to show the greatest improvements in the reaction times. The study also suggested that using caffeine alone may also benefit the individuals. So, make yourself comfortable with a cup of coffee.

Nancy Walker

Nancy holds a Medicine degree and a Masters of Science MS in Infectious Disease and Global Health (MS-IDGH) from Tufts University. She worked as a lecturer for three years before she turned towards medical writing. Her area of interest are infectious diseases; causes, mechanism, diagnosis, treatments and prevention strategies. Most of her writings ensure an easy understanding of uncommon diseases.

Leave a Reply
Your email address will not be published. *

This site uses Akismet to reduce spam. Learn how your comment data is processed.

error: Content is protected !!