Induction of photosensitivity in cultured rat pineal affects Aa-nat regulation.

In a previous investigation we have demonstrated that neonatal rat pineal may become photosensitive if removed from the animal at post-natal day 1 and cultured for 7 days. In the present study we demonstrated that Aa-nat mRNA, the key enzyme in melatonin biosynthetic pathway, is affected by illumination in photosensitive pineal, and Aa-nat transcription in photosensitive pineal, but not in adult or non photosensitive pineals, is up-regulated by BMAL1:CLOCK.