The brain is hotter than previously thought

Until a few days ago we were unaware that there are areas of our brain that are much hotter than expected.

So much so that every day they reach 41 or 42 degrees of temperature, according to an article in the

magazine .

Of course, the brain does not burn at these levels 24 hours a day.

Throughout the day, and depending on neuronal activity, the temperature fluctuates.

Specifically, among the healthy volunteers taken as controls for the study, brain temperature ranged between 36 and 41 degrees, with an average of 38.5 degrees.

On the other hand, in patients who had suffered brain damage due to trauma, the temperature ranged even more, between 32.6 and 42.3 degrees, without changing the mean.

It seems indisputable that brain temperature exceeds the temperature usually recorded in the mouth or armpits (around 36 degrees) by more than two degrees.

The question is: why?

Cells as a heat source

Our body temperature depends almost exclusively on the activity of the organelles that produce energy in our cells: the mitochondria.

In the intense activity of these cellular power plants to generate ATP - the

molecule , necessary for everything to work - a lot of heat is produced.

And it is precisely this heat that maintains body temperature.

In addition, the mitochondria present a series of proteins that dissipate energy.

These proteins, known as UCP (or uncoupling proteins), are very abundant in fatty tissue, especially brown.

Neurons and their accompanying cells (known as glia) consume a large amount of energy and maintain high mitochondrial activity.

In fact, despite accounting for only 2% of the weight of an adult person, the brain accounts for 20% of all the energy we consume throughout the day.

In newborns it can go up to 80%.

Neurons account for only 2% of the weight of an adult person, but 20% of all energy

Therefore, it is not surprising that such consumption is accompanied by a high generation of heat.

Just as it happens with our muscles when we put them into operation with exercise, the more energy consumed, the more heat.

In fact, brain cells contain UCP-rich mitochondria.

These proteins have been associated with cell survival, since they reduce cell damage in the face of changes in metabolic activity.

temperature fluctuates

It's not the first study to suggest that both body and brain temperatures fluctuate throughout the day.

Brain temperature is highest in the morning, drops throughout the afternoon, and reaches its lowest at night.

In addition, the fluctuations also depend on the activities that we are carrying out.

The areas that present the most variation are the deepest, including those where memory resides, such as the hypothalamus.

This study found that traumatic brain injury patients lose some of this ability to fluctuate in temperature.

This loss of capacity has been related to an increased risk of death, possibly due to dysfunctions in mitochondrial activity.

Women's brains are hotter

In general, women have a higher brain temperature than men.

Especially during the luteal phase, that is, between ovulation and menstruation.

Everything indicates that the menstrual cycle and the fluctuation of hormones influence neuronal activity, and this is reflected in brain temperature.

On the other hand, in older people an increase in temperature has been detected in some areas of the brain, especially those related to memory.

Simultaneously, other studies have shown that there is a drop in temperature in other areas, possibly due to defects in the circulation of blood and cerebrospinal fluid.

Blood circulation serves to regulate body temperature, especially the brain.

This is why we turn pale when the environment is cold: because the circulation retracts from the skin, thus preventing heat from being lost.

On the contrary, the circulation in the skin increases when it is hot, in order to dissipate the body temperature through sweating.

can damage neurons

One of the biggest concerns when the fever rises is to control it to avoid, among other things, brain damage.

We now know that certain areas of the brain are warmer than the rest of the body.

Therefore, an increase in body temperature due to fever can make certain parts of the brain, the hottest, unable to dissipate heat well and cell damage occurs.

Although this is a controversial aspect, some studies have already presented evidence showing neuronal damage after hyperthermia phenomena.

Studies on brain temperature open up the possibility of addressing in a more appropriate way the phenomena associated with mitochondrial dysfunction, the accumulation of damaged proteins and neurodegenerative diseases (Parkinson's, Alzheimer's, etc.), thus allowing a better and faster diagnosis of these diseases.

Guillermo López Lluch

This article was originally published on

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