Researchers have just discovered the crucial role that a metabolic pathway plays in Alzheimer’s disease. And their work shows in mice that an amino acid supplement in the form of a dietary supplement can restore spatial memory. It’s a promising way to alleviate the memory loss caused by Alzheimer’s disease.
Scientists from the Laboratory of Neurodegenerative Diseases (CNRS/CEA/University of Paris Saclay) and the Magendie Neurocentre (Inserm/University of Bordeaux) have just highlighted the crucial role of a metabolic pathway in the deterioration of memory in Alzheimer’s disease. Their work, published in Cell Metabolism on Tuesday 3 March 2020, also shows that the intake of a specific amino acid in the form of a dietary supplement restores spatial memory, which was affected in early models of the disease in mice.
The brain consumes a large part of the energy available in our body. Its proper functioning is based on a close cooperation between neurons and the cells of its environment, in particular the astrocytes. The initial phase of Alzheimer’s disease is characterized by a reduction in this energy metabolism, but it is not known whether this deficit can directly contribute to the cognitive symptoms of Alzheimer’s disease.
Restored memory functions in mice
A joint study has shown in a mouse model of Alzheimer’s disease that the reduction of glucose consumption by astrocytes leads to a reduction in the production of L-serine, an amino acid that is produced mainly by these cells in the brain and whose biosynthetic pathway is altered in patients. L-serine is the precursor to D-serine, which is known to stimulate NMDA receptors, which are essential for proper brain function and memory formation. Therefore, by producing less L-serine, astrocytes cause a decrease in the activity of these receptors, resulting in a change in neuronal plasticity and associated memory performance.
The memory functions of the mice were all restored by dietary intake of L-serine.
The scientists also demonstrated that the memory functions of the mice were restored by dietary intake of L-serine. The identification of the role of L-serine in memory disorders and the experimental efficacy of dietary supplements opens the way to new strategies, complementary to drug therapies, to combat the early symptoms of Alzheimer’s disease and other diseases with alterations of brain metabolism, such as Parkinson’s or Huntington’s disease. Since L-serine is available as a dietary supplement, this molecule must be rigorously tested in supervised human clinical trials.