Oleic acid produced in the brain promotes neurogenesis – the generation of new neurons.

Oleic acid is a monounsaturated fatty acid produced in plants and is the primary fatty acid found in olive oil. Interestingly, oleic acid is also produced in the human brain. Findings from a recent study suggest that brain-derived oleic acid activates neural stem cells in the hippocampus, promoting neurogenesis – the generation of new neurons.

The hippocampus is a small organ located within the brain’s medial temporal lobe. It is an important part of the limbic system (the region that regulates emotions) and plays critical roles in memory, learning, and spatial navigation. The neurons in the hippocampus are particularly vulnerable to amyloid-beta plaque accumulation, tau tangle formation, and subsequent atrophy – early indicators of Alzheimer’s disease.

The investigators used spectroscopy, a research tool that uses light scatter to measure concentration, to look for the presence of monounsaturated fatty acids in neural progenitor cells. These cells differ from stem cells in that they can undergo only a limited number of replication cycles. They found that the progenitor cells contained several monounsaturated fatty acids, the most abundant of which was oleic acid. Treating the cells with a chemical that blocked the activity of enzymes involved in oleic acid production dramatically reduced the cells' survival.

Next, they used spectroscopy to look for the presence of monounsaturated fatty acids in the brains of mice. They found an abundance of the fatty acids, especially oleic acid, in the dentate gyrus, the region of the hippocampus where neurogenesis occurs. Then, using homology modeling (a type of computer-based study technique) they observed that oleic acid bound to TLX, a protein in neural stem cells that regulates neurogenesis, switching on the protein’s activity and driving the production of new neurons.

These findings suggest that oleic acid produced in the brain activates neurogenesis. Therapeutic modulation of TLX may be a means to counteract the effects of impaired neurogenesis in age-related cognitive decline, depression, Alzheimer’s disease, and other conditions. Brain-derived neurotropic factor, or BDNF, also promotes neurogenesis. Learn more about BDNF and the lifestyle behaviors that promote its production in our overview article.

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