🧠 Brain: another source of energy for neurons besides sugar

The human brain is an extremely active organ, requiring a constant supply of fuel. For a long time, sugar was considered its only energy source. Yet, a recent observation contradicts this established view: neurons possess the surprising ability to produce and use their own fat reserves.

This discovery fundamentally alters our understanding of brain metabolism. Until now, the scientific community thought that nerve cells relied solely on glucose to function. Work by an international team reveals that these cells can also burn lipids. Even better, when they lack resources, they are capable of producing them by recycling internal components, a mechanism that was unexpected until now.


This lipid production process relies on the action of a specific protein, named DDHD2. It acts as an essential regulator, allowing neurons to generate a flow of saturated fats. These lipids then serve as fuel to power cellular activities and ensure effective communication between nerve cells. Without this functional protein, the entire energy chain is compromised.

The importance of DDHD2 is highlighted by a rare neurological condition, hereditary spastic paraplegia type 54. In affected individuals, this protein is defective. Neurons then lose their ability to synthesize the necessary fats. This energy deficiency translates into a progressive weakening of cells and early difficulties, particularly in movement coordination and cognitive functions. The link between this type of dysregulation and neurological diseases is detailed at the end of the article.

Faced with this dysfunction, researchers tested a simple approach: directly providing neurons with supplements of specific fatty acids. In the laboratory, this supplementation allowed damaged cells to regain their energy level in just forty-eight hours. Neuronal functions, severely impaired, showed clear signs of improvement, opening a concrete therapeutic path.

Merja Joensuu, who led this work, indicates that this lipid metabolic pathway is fundamental for healthy neurons. Her team now plans to evaluate the safety and efficacy of these fatty acid-based treatments in preclinical models. The goal is to verify if this strategy could be transposed to humans and benefit other brain disorders currently without treatment.

Giuseppe Balistreri, a collaborator on the study, mentions the use of non-invasive imaging technologies to accelerate the development of this potential therapy. These advances, published in Nature Metabolism, do not just revise biology textbooks. They offer hope for developing new methods to protect and restore brain functions, potentially changing the daily lives of many patients.

Lipids, an underappreciated fuel for cells

Lipids, commonly called fats, play multiple roles in the body. Beyond their function as an energy reserve, they are essential components of cellular membranes. In the brain, these membranes are particularly rich in lipids, which influences the fluidity and communication between neurons. Certain specific fatty acids are thus indispensable for the proper development and functioning of the nervous system.

Lipid metabolism is a finely regulated process. Cells can either obtain them through diet or synthesize them themselves from other molecules. This internal production, or lipogenesis, requires significant energy expenditure. It is often activated when external resources are limited, allowing the cell to maintain its vital activities.

In the neuronal context, the use of lipids as a direct source of energy is a relatively new concept. Traditionally, it was thought that neurons, unlike muscles or the liver, could not efficiently oxidize fats. This discovery reveals that they do indeed possess the necessary enzymes to do so, broadening the palette of energy substrates for the brain.

This ability to exploit lipids could be an adaptation to cope with situations of stress or glucose scarcity. Understanding how neurons manage this dual supply of sugar and fat is therefore a key to grasping the brain's resilience in the face of aggression or disease.