While cancer “kidnaps” the brain and steals our motivation

A cruel consequence of cancer at the advanced stage is a profound apathy that many patients experience losing interest in highly appreciated activities.

This symptom is part of a syndrome called cachexia, which affects about 80% of patients with terminal carcinoma, leading to a serious loss of muscle mass and weight, leaving patients extremely thin, even with proper nutrition.

This loss of motivation not only deepens the suffering of patients, but is isolating them from family and friends.

Since patients have difficulty engaged in demanding therapies that require effort and persistence, this also overloads family members and complicates the treatment.

Doctors usually presuppose that when patients with advanced stadium cancer turn their lives, this is an inevitable psychological response to physical deterioration.

What if apathy was not only a consequence of the physical decline, but an integral part of the disease itself?

In our new research published, my colleagues and I find something extraordinary: cancer not only consumes the body, but kidnaps a specific brain circuit that controls the motivation.

Our discoveries, published on Science Magazine, challenge decades of hypotheses and suggest that it may be possible to restore what many cancer patients describe as the most devastating loss: the desire to commit with life.

Separate fatigue from physical decline

To reveal the puzzle of apathy in Cancer Kichessia, we had to trace in the exact way in which inflammation travels in the body and observing the lively brain while the disease progresses – something impossible to do in humans.

However, neuroscientists have advanced technologies that make it possible in mice.

Modern neuroscience offers us a powerful arsenal of tools to study how diseases alter the brain activity in mice.

Scientists can map the brain of whole cells, keep track of neural activity during behaviors and activate or disable neurons accurately.

We use these tools on a cachexia mud model induced by cancer to study the effects of brain disease and motivation.

Identify the motivation circuit

We have identified a small region of the brain called the postrema area, which acts as a detector of brain inflammation.

As a tumor grows, it releases cytokines – molecules that trigger inflammation – in the bloodstream.

The postrema area does not have the typical bloodphalical barrier that prevents toxins, pathogens and other molecules in the body, allowing them to directly monitor the circulating inflammatory signs.

When the postrema area detects an increase in these inflammatory molecules, it triggers a neural waterfall that affects various brain regions, culminating in the suppression of the release of dopamine in the center of motivation of the brain – the core thus called Accumens.

Although often misunderstood as a “pleasure chemist”, dopamine is more associated with the impulse or the desire to make efforts to obtain prizes: includes the convenient internal balance towards the action.

How do we measure the effort on mice

We observe this change directly with two quantitative tests, based on the principles of the behavioral economy to measure the effort.

In the first, the mice had to repeatedly insert the muzzle in a food compartment, with an increasing number of attempts necessary to receive each power ball.

In the second test, they crossed a bridge between two fountains, which were emptying with use, forcing animals to change laterally, as someone who collected a tree until he exhausted a tree.

While cancer advanced, the mice still sought easy prizes, but quickly abandoned tasks that required greater effort.

At the same time, we saw the dopamine levels fall in real time, reflecting the fall in the arrangement of animals to fight for the prizes.

Our results suggest that cancer does not “wear” the brain in general, but sends specific inflammatory signs that the brain detects.

The brain therefore responds quickly reducing dopamine levels, reducing motivation.

This coincides with what patients report: “Everything seems too difficult”.

Restore the motivation in the advanced phases of the disease

Perhaps the most exciting is that we find various ways to restore the motivation in cancer cachexia mice, even with growing cancer.

First of all, when it genetically turns off the neurons sensitive to inflammation in the postrema area or by directly stimulating neurons to release dopamine, we can restore normal motivation on mice.

Secondly, we discovered that the administration of a drug that blocks a specific cytokine – similar to the treatments already approved by the Anvisa equivalent American agency) for arthritis – was effective.

Although the remedy does not invert physical wear, it has restored the arrangement of mice to seek rewards.

Although these results are based on animal models, they suggest a possibility of treatment for people: by directing this specific circuit between inflammation and dopamine, the quality of life of patients with cancer can also be improved when the disease remains incurable.

The border between physical and psychological symptoms is an artificial division.

Cancer ignores this separation using inflammation to take control of the circuits that guide the desire to act. But our results suggest that these messages can be intercepted – and the circuits, restored.

Rethink apathy in diseases

Our discovery has implications that go beyond cancer.

The inflammatory molecule that also causes the loss of motivation in cancer is involved in many other conditions – by autoimmune diseases such as rheumatoid arthritis to chronic infections and depression.

This same cerebral circuit can explain the debilitating apathy that millions of people with chronic diseases face.

The apathy triggered by inflammation may have originally evolved as a protective mechanism. When the first humans had to face acute infections, the reduction of motivation made sense: he saved the energy and directed the resources to recovery.

But what has once helped to survive short -term diseases becomes harmful when inflammation persists, as in cancer and other diseases. Instead of helping with recovery, prolonged apathy deepens suffering, worsening the results and quality of life.

Although the application of these discoveries in human therapies requires further research, they reveal a promising treatment objective. By interccccc. inflammatory or modular cerebral circuits, scientists can be able to restore patient impulse.

For patients and families who help the motivation to disappear, this possibility offers something powerful: the hope that even with the progress of the disease, the essence of who we are can be recovered.

* Adam Kepecs is a professor of neuroscience and psychiatry at the University of Washington in St. Louis (USA).

This entry was originally published on the academic news website The conversation and republished here with a Creative Commons license. Read the original version here (in English).

Source: Terra

Ben

Ben Stock is a lifestyle journalist and author at Gossipify. He writes about topics such as health, wellness, travel, food and home decor. He provides practical advice and inspiration to improve well-being, keeps readers up to date with latest lifestyle news and trends, known for his engaging writing style, in-depth analysis and unique perspectives.