Moderate exposure to sunlight improves motor learning and long-term memory in mice

A short summary from the article:

Upon exposure of the skin to UV rays, urocanic acid (UCA) levels are increased. UCA crosses the blood-brain barrier and enters neurons, where it is converted to glutamate in a multistep metabolic pathway. As a result, glutamate levels increase, and in some glutamatergic synapses, this leads to increased packaging and release of this neurotransmitter. This pathway is necessary for sunlight to boost motor learning and long-term memory in mice.

And the journal article that this article is referencing:

Moderate UV Exposure Enhances Learning and Memory by Promoting a Novel Glutamate Biosynthetic Pathway in the Brain. Zhu et al. Cell. 6/14/2018