Stomatogastric nervous system
Encyclopedia
The Stomatogastric Nervous System (STNS) is a commonly studied neural network
composed of several ganglia
in arthropod
s that controls the motion of the gut and foregut. The network of neurons acts as a central pattern generator
. It is a model system for motor pattern generation because of the small number of cells, which are comparatively large and can be reliably identified. The system is composed of the stomatogastric ganglion (STG), oesophageal ganglion and the paired commissural ganglia.
Because of the many similarities between vertebrate and invertebrate systems, especially with regards to basic principles of neuronal function, invertebrate model systems such as the crustacean stomatogastric nervous system continue to provide key insight into how neural circuits operate in the numerically larger and less accessible vertebrate CNS.
Understanding how neuronal networks enable animals and humans to make coordinated movements is a continuing goal of neuroscience research. The stomatogastric nervous system of decapod crustaceans, which controls aspects of feeding, has contributed significantly to the general principles guiding our present understanding of how rhythmic motor circuits operate at the cellular level.
Rhythmic behaviors include all motor acts that at their core involve a rhythmic repeating set of movements. The circuits underlying such rhythmic behaviors, central pattern generator
s (CPGs), all operate on the same general principles. These networks remain rhythmic in the completely isolated nervous system, even in the absence of all rhythmic neuronal input, including feedback from sensory systems. Although the details differ in each circuit, all CPGs
use the same set of cellular-level mechanisms for circuit construction. More importantly, CPG
circuits are usually not dedicated to producing a single neuronal activity pattern. This flexibility results largely from the ability of different neuromodulators to change the cellular and synaptic properties of individual circuit neurons. When the properties of circuit components are changed, the output of the circuit itself is modified. These aspects of CPG
operation are often shared by other circuits, enabling a general understanding of neuronal circuit operation.
The STNS contains a set of distinct but interacting motor circuits. The understanding of this multifunctional network contributed importantly to the general understanding of neural circuit operation. The value of this system has resulted from its accessibility, the use of several innovative techniques, and the combined research effort of around 15 laboratories over the past ~30 years.
Neural network
The term neural network was traditionally used to refer to a network or circuit of biological neurons. The modern usage of the term often refers to artificial neural networks, which are composed of artificial neurons or nodes...
composed of several ganglia
Ganglion
In anatomy, a ganglion is a biological tissue mass, most commonly a mass of nerve cell bodies. Cells found in a ganglion are called ganglion cells, though this term is also sometimes used to refer specifically to retinal ganglion cells....
in arthropod
Arthropod
An arthropod is an invertebrate animal having an exoskeleton , a segmented body, and jointed appendages. Arthropods are members of the phylum Arthropoda , and include the insects, arachnids, crustaceans, and others...
s that controls the motion of the gut and foregut. The network of neurons acts as a central pattern generator
Central pattern generator
Central pattern generators are neural networks that produce rhythmic patterned outputs without sensory feedback. CPGs have been shown to produce rhythmic outputs resembling normal "rhythmic motor pattern production" even in isolation from motor and sensory feedback from limbs and other muscle...
. It is a model system for motor pattern generation because of the small number of cells, which are comparatively large and can be reliably identified. The system is composed of the stomatogastric ganglion (STG), oesophageal ganglion and the paired commissural ganglia.
Because of the many similarities between vertebrate and invertebrate systems, especially with regards to basic principles of neuronal function, invertebrate model systems such as the crustacean stomatogastric nervous system continue to provide key insight into how neural circuits operate in the numerically larger and less accessible vertebrate CNS.
Understanding how neuronal networks enable animals and humans to make coordinated movements is a continuing goal of neuroscience research. The stomatogastric nervous system of decapod crustaceans, which controls aspects of feeding, has contributed significantly to the general principles guiding our present understanding of how rhythmic motor circuits operate at the cellular level.
Rhythmic behaviors include all motor acts that at their core involve a rhythmic repeating set of movements. The circuits underlying such rhythmic behaviors, central pattern generator
Central pattern generator
Central pattern generators are neural networks that produce rhythmic patterned outputs without sensory feedback. CPGs have been shown to produce rhythmic outputs resembling normal "rhythmic motor pattern production" even in isolation from motor and sensory feedback from limbs and other muscle...
s (CPGs), all operate on the same general principles. These networks remain rhythmic in the completely isolated nervous system, even in the absence of all rhythmic neuronal input, including feedback from sensory systems. Although the details differ in each circuit, all CPGs
Central pattern generator
Central pattern generators are neural networks that produce rhythmic patterned outputs without sensory feedback. CPGs have been shown to produce rhythmic outputs resembling normal "rhythmic motor pattern production" even in isolation from motor and sensory feedback from limbs and other muscle...
use the same set of cellular-level mechanisms for circuit construction. More importantly, CPG
Central pattern generator
Central pattern generators are neural networks that produce rhythmic patterned outputs without sensory feedback. CPGs have been shown to produce rhythmic outputs resembling normal "rhythmic motor pattern production" even in isolation from motor and sensory feedback from limbs and other muscle...
circuits are usually not dedicated to producing a single neuronal activity pattern. This flexibility results largely from the ability of different neuromodulators to change the cellular and synaptic properties of individual circuit neurons. When the properties of circuit components are changed, the output of the circuit itself is modified. These aspects of CPG
Central pattern generator
Central pattern generators are neural networks that produce rhythmic patterned outputs without sensory feedback. CPGs have been shown to produce rhythmic outputs resembling normal "rhythmic motor pattern production" even in isolation from motor and sensory feedback from limbs and other muscle...
operation are often shared by other circuits, enabling a general understanding of neuronal circuit operation.
The STNS contains a set of distinct but interacting motor circuits. The understanding of this multifunctional network contributed importantly to the general understanding of neural circuit operation. The value of this system has resulted from its accessibility, the use of several innovative techniques, and the combined research effort of around 15 laboratories over the past ~30 years.