The lateral giant interneuron (LG) is an

interneuron Interneurons (also called internuncial neurons, association neurons, connector neurons, or intermediate neurons) are neurons that are not specifically motor neurons or sensory neurons. Interneurons are the central nodes of neural circuits, enab ...

in the

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

nerve A nerve is an enclosed, cable-like bundle of nerve fibers (called axons). Nerves have historically been considered the basic units of the peripheral nervous system. A nerve provides a common pathway for the Electrochemistry, electrochemical nerv ...

cord of

crayfish Crayfish are freshwater crustaceans belonging to the infraorder Astacidea, which also contains lobsters. Taxonomically, they are members of the superfamilies Astacoidea and Parastacoidea. They breathe through feather-like gills. Some spe ...

lobster Lobsters are Malacostraca, malacostracans Decapoda, decapod crustaceans of the family (biology), family Nephropidae or its Synonym (taxonomy), synonym Homaridae. They have long bodies with muscular tails and live in crevices or burrows on th ...

shrimp A shrimp (: shrimp (American English, US) or shrimps (British English, UK)) is a crustacean with an elongated body and a primarily Aquatic locomotion, swimming mode of locomotion – typically Decapods belonging to the Caridea or Dendrobranchi ...

of the order

Decapoda The Decapoda or decapods, from Ancient Greek δεκάς (''dekás''), meaning "ten", and πούς (''poús''), meaning "foot", is a large order of crustaceans within the class Malacostraca, and includes crabs, lobsters, crayfish, shrimp, a ...

and their relatives in the

crustacean Crustaceans (from Latin meaning: "those with shells" or "crusted ones") are invertebrate animals that constitute one group of arthropods that are traditionally a part of the subphylum Crustacea (), a large, diverse group of mainly aquatic arthrop ...

class

Malacostraca Malacostraca is the second largest of the six classes of pancrustaceans behind insects, containing about 40,000 living species, divided among 16 orders. Its members, the malacostracans, display a great diversity of body forms and include crab ...

. 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 these organisms known as the "

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

." When the

sensory hair Sensory may refer to: Biology * Sensory ecology, how organisms obtain information about their environment * Sensory neuron, nerve cell responsible for transmitting information about external stimuli * Sensory perception, the process of acquiri ...

s of the tail fan of crayfish are stimulated, the LG activates the

motor neuron A motor neuron (or motoneuron), also known as efferent neuron is a neuron whose cell body is located in the motor cortex, brainstem or the spinal cord, and whose axon (fiber) projects to the spinal cord or outside of the spinal cord to directly o ...

s that control flexion movements of the

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

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; also referred to as "response time") is measured ...

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

electrical synapse An electrical synapse, or gap junction, is a mechanical and electrically conductive synapse, a functional junction between two neighboring neurons. The synapse is formed at a narrow gap between the pre- and postsynaptic neurons known as a gap junc ...

References

* * * Neurons Crayfish {{neuroanatomy-stub

See also

References