HealthyPIG Magazine

Nerve cells (also called neurons) in the body communicate with each other through chemical messengers called neurotransmitters. Neurotransmitters control nearly everything we do, influencing our thoughts and feelings, and coordinating our actions. A neurotransmitter called a neuropeptide.
Orexins are neuropeptides produced in a part of the brain called the hypothalamus. Of the billions of cells in the brain, only 10,000 to 20,000 produce orexin. These cells produce two types of orexin called orexin-A and orexin-B.
These neuropeptides were discovered by two groups around the same time, so they have two interchangeable names in the scientific community. One group chose the name "orexin," taken from the Greek "orexis," meaning appetite. Another group calls these neuropeptides hypocretins because they are found in the hypothalamus. Therefore, orexin-A and orexin-B are commonly known as hypocretin-1 and hypocretin-2.