Protocerebrum
- Pronunciation
- /PROH-toh-SER-uh-brum/
- Category
- Anatomy
- Singular
- protocerebrum
- Plural
- protocerebra
Definition
The (first) segment of the brain, derived from the preoral ganglia of the first embryonic neuromere; it innervates the , ocelli, and most of the capsule, and is divided into the (for visual processing) and the central body (involved in navigation and motor coordination). In insects, the protocerebrum sits to the deutocerebrum and tritocerebrum and integrates sensory information from the and ocelli.
Etymology
From Greek proto- (first) + Latin (brain)
Example
In the fruit fly Drosophila melanogaster, the protocerebrum contains the mushroom bodies—paired neuropils essential for olfactory learning and memory—and receives massive input from the that process motion and color information from the .
Related Terms
- deutocerebrum
- tritocerebrum
- Optic lobe
- mushroom body
- central body
- neuromere
- supraesophageal ganglion
- ocellus
Usage Notes
The protocerebrum is sometimes referred to loosely as the 'forebrain' of insects, but this is imprecise; it is more accurate to reserve 'protocerebrum' for the specific neuromere-derived structure. In some crustaceans and chelicerates, homologous regions exist but may show different regional specializations. The term applies broadly across Panarthropoda (Arthropoda + Onychophora + Tardigrada), though most detailed neuroanatomical work has been done in insects.