Striking similarities in brain structures across invertebrates

The fundamental structures underlying learning and memory in the brains of invertebrates as different as a fruit fly and an earthworm are remarkably similar, according to neuroscientists. It turns out that the structure and function of brain centers responsible for learning and memory in a wide range of invertebrate species may possibly share the same fundamental characteristics. The brain centers are paired, lobed structures first discovered in insects and known as mushroom bodies. These centers occur in the forebrains of arthropods, as well as in marine worms and flatworms. The team analyzed protein expression in mushroom bodies. It found that the abundance of three proteins called DC0, Leo and CaMKII was conserved in the mushroom bodies across these invertebrate groups. These same proteins also are thought to be critical for learning and memory in humans, and are implicated in neurological disorders such as Alzheimer’s disease, Down syndrome and Angelman syndrome. This means it is possible that brain structures responsible for learning and memory in nearly all animals that possess those including humans, but with the possible exception of mollusks may have originated from one ancestor and have since undergone divergent evolution into centers of various complexity.