Hydra Organisms Reveal Sleep Can Exist Without a Brain

When we discuss sleep, we often bring up the brain. Sleep is, after all, linked to the Central Nervous System (CNS). And in studies that involve sleep issues, we look specifically at the mind and the role that it plays. For a long time, it was believed that sleep was important solely because of the brain. 

However, a new study in Hydra organisms shows that the minuscule creatures still sleep, despite not having a brain. Namely, the Hydra is a minuscule underwater organism that attaches parts of itself to a rock at the very bottom of a body of water, and it lives off of water fleas that it entraps in its mouth. 

Well, quite recently, it’s been discovered that this brainless organism sleeps for periods of time. To be more precise, the Hydra goes into a state of rest that meets the scientific requirements of the definition of sleep. 

Of course, in human beings, the brain has a lot to do with sleep. Sleep is important when it comes to cognitive functioning. The longer we go without sleep, the more difficult it is to operate normally. Obviously, sleep is vital for the proper functioning of most of our organs. Nevertheless, the emphasis is mostly placed on its importance when it comes to the brain. 

The fact that an organism exists without a brain and yet still requires sleep may change the way we think about sleep. Still, it doesn’t change the way we understand the relationship between human brains and rest.