The medial giant interneuron (MG) is an interneuron in the

abdominal The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the torso ...

nerve cord of crayfish. It is part of the system that controls the

caridoid escape reaction The caridoid escape reaction, also known as lobstering or tail-flipping, refers to an innate escape mechanism in marine and freshwater crustaceans such as lobsters, krill, shrimp and crayfish. The reaction, most extensively researched in crayfis ...

of crayfish, clawed lobsters, and other decapod

crustacean Crustaceans (Crustacea, ) form a large, diverse arthropod taxon which includes such animals as decapods, seed shrimp, branchiopods, fish lice, krill, remipedes, isopods, barnacles, copepods, amphipods and mantis shrimp. The crustacean group can ...

s. Crayfish have a pair of medial giants running the length of the entire animal, and are the largest neurons in the animal. When a crayfish is given a sudden visual or tactile stimulus to the front part of the animal, the MG activates fast flexor motor neurons that cause the

abdomen The abdomen (colloquially called the belly, tummy, midriff, tucky or stomach) is the part of the body between the thorax (chest) and pelvis, in humans and in other vertebrates. The abdomen is the front part of the abdominal segment of the to ...

to flex, resulting in the crayfish moving directly backward, away from the source of the stimulation. This connection was first demonstrated by C. A. G. Wiersma in the red swamp crayfish, ''

Procambarus clarkii ''Procambarus clarkii'', known variously as the red swamp crayfish, Louisiana crawfish or mudbug, is a species of cambarid crayfish native to freshwater bodies of northern Mexico, and southern and southeastern United States, but also introduce ...

''. The medial giant interneurons are less well studied than the

lateral giant neuron The lateral giant interneuron (LG) is an interneuron in the abdominal nerve cord of crayfish, lobsters, shrimp of the order Decapoda and their relatives in the crustacean class Malacostraca. It is part of the system that controls a specia ...

s, which trigger a similar escape behavior.

References

* * * {{ref end Neurons Crayfish

See also

References