Cerebral ganglion

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 processes 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
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 structural 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

References

  1. ↑ In a standard scheme, the CNG and GNG are both considered the brain. The CRG minus the optic lobe constitutes the cerebrum, similar to how the cerebrum is a part of the brain in vertebrates.
  1. 1 2 3 Ito, Kei; Shinomiya, Kazunori; Ito, Masayoshi; Armstrong, J. Douglas; Boyan, George; Hartenstein, Volker; Harzsch, Steffen; Heisenberg, Martin; Homberg, Uwe; Jenett, Arnim; Keshishian, Haig; Restifo, Linda L.; Rössler, Wolfgang; Simpson, Julie H.; Strausfeld, Nicholas J.; Strauss, Roland; Vosshall, Leslie B. (19 February 2014). "A systematic nomenclature for the insect brain". Neuron. 81 (4): 755–765. doi:10.1016/j.neuron.2013.12.017. PMID 24559671.; Supplemental Information, which includes details of this nomenclature.
  2. ↑ Makoto Mizunami, Fumio Yokohari, Masakazu Takahata (1999). "Exploration into the Adaptive Design of the Arthropod "Microbrain"". Zoological Science. 16 (5): 703–709. doi:10.2108/zsj.16.703. S2CID 86501328.{{cite journal}}: CS1 maint: multiple names: authors list (link)
  3. 1 2 3 Meyer, John R. "The Nervous System". General Entomology course at North Carolina State University. Department of Entomology NC State University. Archived from the original on 2017-02-02. Retrieved 11 November 2013.
  4. 1 2 Homberg, U; Christensen, T A; Hildebrand, J G (1989). "Structure and Function of the Deutocerebrum in Insects". Annual Review of Entomology. 34: 477–501. doi:10.1146/annurev.en.34.010189.002401. PMID 2648971.
  5. ↑ "Invertebrate Brain Platform". RIKEN BSI Neuroinformatics Japan Center.
  6. ↑ "Deutocerebrum". Flybrain.
  7. ↑ "Deutocerebrum". Invertebrate Brain Platform. Chelicerata, with their missing antennae, have a very reduced (or absent) deutocerebrum.
  8. ↑ Posnien, N; Hunnekuhl, VS; Bucher, G (26 September 2023). "Gene expression mapping of the neuroectoderm across phyla - conservation and divergence of early brain anlagen between insects and vertebrates". eLife. 12 e92242. doi:10.7554/eLife.92242. PMC 10522337. PMID 37750868.
  9. ↑ Bridi, Jessika C.; Ludlow, Zoe N.; Kottler, Benjamin; Hartmann, Beate; Vanden Broeck, Lies; Dearlove, Jonah; Göker, Markus; Strausfeld, Nicholas J.; Callaerts, Patrick; Hirth, Frank (11 August 2020). "Ancestral regulatory mechanisms specify conserved midbrain circuitry in arthropods and vertebrates". Proceedings of the National Academy of Sciences. 117 (32): 19544–19555. Bibcode:2020PNAS..11719544B. doi:10.1073/pnas.1918797117. PMC 7431035. PMID 32747566.
  10. ↑ Sweeney, Lora B.; Luo, Liqun (September 2010). "'Fore Brain: A Hint of the Ancestral Cortex". Cell. 142 (5): 679–681. doi:10.1016/j.cell.2010.08.024. PMID 20813256.

Further reading