// Workers AI · dad joke modeWhat did the cerebral ganglion say? "I've got a lot on my mind".

Further information: Arthropod head problem

The cerebral ganglion (CNG; also cerebral ganglia, supra(o)esophageal ganglia [SPG], arthropod brain, or microbrain) is the main part of the brain in most insect species and in some other closely related arthropods, such as myriapods and crustaceans. It receives and processs information from the first, second, and third metameres. It is connected to the gnathal ganglion (GNG), a part of the CNS in the head which may or may not be considered part of the brain.

The cerebral ganglion consists of three parts, each a pair of ganglia that may be more or less pronounced, reduced, or fused depending on the genus:

Locust brain

• The protocerebrum, associated with the eyes (compound eyes and ocelli). Directly associated with the eyes is the optic lobe, as the visual center of the brain.
• The deutocerebrum processes sensory information from the antennae. It consists of two parts, the antennal lobe and the dorsal lobe. The dorsal lobe also contains motor neurons which control the antennal muscles.
• The tritocerebrum integrates sensory inputs from the previous two pairs of ganglia. In locusts and cockroaches, lobes of the tritocerebrum split to circumvent the esophagus and begin the subesophageal ganglion.

Supraesophageal ganglion (5), Subesophageal ganglion (31)

The cerebral ganglion lies dorsal to the esophagus in locusts and cockroaches. Contrary to its "supraesophageal" name, it is penetrated by the esophagus during development and remains so in other groups of insects (flies, bees, moths, etc.). In locusts and cockroaches, the parts below the esophagus only remain as thin commissures, hence the original perception of it lying above the esophagus.

The gnathal ganglion continues the nervous system and lies ventral to the esophagus. Finally, the segmental ganglia of the ventral nerve cord are found in each body segment as a fused ganglion; they provide the segments with some autonomous control.

Homology

Similarities of gene expression patterns between insect and vertebrate/mammalian brain indicate that many structual elements derive from common building blocks inherited from a common bilaterian ancestor. For example, the gene circuit defining the midbrain-hindbrain boundary in vertebrates and some other chordates is orthologous to the gene circuit that defines either the deutocerebral–tritocerebral boundary (antennal/intercalary parasegment boundary) or the antennal-ocular boundary ("insect head boundary", IHB) in insects. There is also a correspondence in neural circuits and behavioral functions.

The mushroom bodies of the protocerebrum are homologous to the vertebrate cerebral cortex, according to expression profiling by image registration.

See also

• Lateral horn of insect brain
• Mushroom bodies
• Virtual Fly Brain
• Drosophila connectome

Further reading

• Erber, J.; Menzel, R. (1977). "Visual interneurons in the median protocerebrum of the bee". Journal of Comparative Physiology. 121 (1): 65–77. doi:10.1007/bf00614181. S2CID 34198518.
• Wong, Allan M., Jing W. Wang, and Richard Axel (2002). "Spatial Representation of the Glomerular Map in the Drosophila Protocerebrum". Cell. 109 (2): 229–241. doi:10.1016/S0092-8674(02)00707-9. PMID 12007409.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Malun, D.; Waldow, U.; Kraus, D.; Boeckh, J. (1993). "Connections between the deutocerebrum and the protocerebrum, and neuroanatomy of several classes of deutocerebral projection neurons in the brain of male Periplaneta americana". J. Comp. Neurol. 329 (2): 143–162. doi:10.1002/cne.903290202. PMID 8454728. S2CID 20142144.
• Flanagan, Daniel; Mercer, Alison R. (1989). "Morphology and response characteristics of neurones in the deutocerebrum of the brain in the honeybeeApis mellifera". Journal of Comparative Physiology A. 164 (4): 483–494. doi:10.1007/bf00610442. S2CID 23327875.
• Childress, Steven A.; B. McIver, Susan (1984). "Morphology of the deutocerebrum of female Aedes aegypti (Diptera: Culicidae)". Canadian Journal of Zoology. 62 (7): 1320–1328. Bibcode:1984CaJZ...62.1320C. doi:10.1139/z84-190.
• Technau, Gerhard (2008). Technau, Gerhard M (ed.). Brain Development in Drosophila melanogaster. Advances in Experimental Medicine and Biology (in Dutch). Vol. 628. New York Austin, Tex: Springer Science+Business Media Landes Bioscience. doi:10.1007/978-0-387-78261-4. ISBN 978-0-387-78260-7. OCLC 314349837.
• Aubele, Elisabeth, and Nikolai Klemm (1977). "Origin, destination and mapping of tritocerebral neurons of locust". Cell and Tissue Research. 178 (2): 199–219. doi:10.1007/bf00219048. PMID 66098. S2CID 22872816.{{cite journal}}: CS1 maint: multiple names: authors list (link)
• Chaudonneret, J. "Evolution of the insect brain with special reference to the so-called tritocerebrum." Arthropod brain. Wiley, New York (1987): 3-26.
• "Behavioral Neuroscience, lecture on Honey Bee and its behavior - Neuroanatomy". Retrieved 2019-02-08.

External links

• "Suboesophageal Ganglion". flybrain.
• "Dissecting insect brain for in vivo electrophysiology". YouTube. Neuronal Systems Lab, Center for Neural and Cognitive Systems, University of Hyderabad. 27 June 2021.