The lateral giant interneuron (LG) 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, lobsters, shrimp of the order Decapoda and their relatives in the

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 ...

class

Malacostraca Malacostraca (from New Latin; ) is the largest of the six classes of crustaceans, containing about 40,000 living species, divided among 16 orders. Its members, the malacostracans, display a great diversity of body forms and include crabs, l ...

. It is part of the system that controls a special kind of

escape reflex Escape reflex, or escape behavior, is any kind of escape response found in an animal when it is presented with an unwanted stimulus. It is a simple reflectory reaction in response to stimuli indicative of danger, that initiates an escape motion of ...

of these organisms known as 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 ...

." When the sensory hairs of the tail fan of crayfish are stimulated, the LG activates the motor neurons that control flexion movements of 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 ...

in a way that propels the crayfish away from the source of the stimulation. The LG bypasses the main neural system that controls locomotion, thus shortening the

reaction time Mental chronometry is the scientific study of processing speed or reaction time on cognitive tasks to infer the content, duration, and temporal sequencing of mental operations. Reaction time (RT; sometimes referred to as "response time") is meas ...

. The lateral giant connection to motor giant fast flexor neurons was the first known example of an

electrical synapse Electricity is the set of physical phenomena associated with the presence and motion of matter that has a property of electric charge. Electricity is related to magnetism, both being part of the phenomenon of electromagnetism, as described by ...

References

* * * Neurons Crayfish {{neuroanatomy-stub

See also

References