A decrease in the level of Menin in the hypothalamus may play a role in aging, according to a study published in the journal PLOS Biology. Menin is known to be a key inhibitor of hypothalamic neuroinflammation. The study found that reduced Menin activity in younger mice resulted in increased hypothalamic neuroinflammation, reductions in bone mass and skin thickness, cognitive decline and modestly decreased lifespan. The study also found that the decline in Menin led to reduced levels of the amino acid D-serine, which has been identified as a neurotransmitter. The study found that reversing age-related Menin loss in elderly mice led to improved skin thickness and bone mass and better learning and cognition. Dietary supplementation with D-serine also led to similar benefits on cognition. The study authors concluded that the decline in Menin expression in the hypothalamus with age may be a driving factor of aging and that further research is needed on the potential use of D-serine as a therapeutic for cognitive decline.