Therefore, if you're planning a long journey, you should always apply for the Russian visa before you leave. It's possible to get a tourist visa support at any moment before your journey, however, you can only apply for a tourist visa not earlier than 90 days before the date of your first entry to Russia.
Serotonin is a common neuromediator in the brain. It belongs to the group of so-called biogenic amines, relatively simple chemicals that facilitate the transfer of signals between the cells of the body.
As a neurotransmitter, serotonin helps to relay messages from one area of the brain to another. Because of the widespread distribution of its cells, it is believed to influence a variety of psychological and other body functions.