protocerebrum

The protocerebrum is the foremost segment of an insect's brain, responsible for innervating the compound eyes. In lower crustaceans, it's the ganglion that gives rise to the optic nerve. In arthropods, the brain is divided into three main regions: the protocerebrum, deutocerebrum, and tritocerebrum. The protocerebrum, located at the anterior, receives nerves from the eyes and other organs. It contains centers called neuropils, such as the optic centers, which integrate information from the anterior sense organs, particularly the eyes, and control movement. These neuropils are also centers for initiating complex behaviors. Neurosecretory cells within the protocerebrum of insects manufacture a hormone that regulates molting and development.12