Renz L. Salumbre

4BIO-6

CENTRAL PATTERN GENERATOR

Definition

Generally, a central pattern generator is a lattice of neurons that functions for the

production of recurring output. Or in other words, it generates repetitive patterns.

Specifically, it is a small neural circuit in a ganglion that specifies the particular motor

output pattern for a number of physiological systems or structures for a particular

behavior pattern; it also accounts for the modulation observed moment-to-moment,

which, in turn produce several different physical actions depending on the needs of

the animal. The theory of the central pattern generator shows that there is a basic

rhythmic pattern produced in these networks, which basically translates to observable

behavior such as locomotion.

A central pattern generator, or generally rhythmic generator, have the following

attributes: Two or more processes that interact such that each process sequentially

increases and decreases; and lastly, that, as a result of this interaction, the system

repeatedly returns to its starting condition.

Below, the following diagram exhibits a typical central pattern generator in the

muscles of the wings of crickets. Central pattern generator is precisely the reason and

the working mechanism behind the characteristic pulse rhythms in the songs of

crickets generated in the meso-thoracic ganglion. A command signal is produced in

the brain that basically sets the central pattern generator going. Once started the song

pattern behavior is produced by the output of motor units from the central pattern

generator.

Properties of Central Pattern Generators

It has been shown above that what characterizes central pattern generators is

their two or more processes which sequentially decreases or increases and the

resulting interaction happening in the generator returns the structure to its

starting condition.

Role in Behavior

Central pattern generators may explain the usual functions of some organisms.

As is aforementioned, the pulse rhythm songs of crickets are generated by the

action of central pattern generators. Other activities such as swimming, moving,

walking, running or flying account for the importance of central pattern

generators. These activities have also been shown to have been modified in

response to sensory feedback.

Some Examples of Central Pattern Generators

Central pattern generators are gaining a momentum in research owing to its

fascinating properties in how it can rationalize simple rhythmic activities which

men tend to ignore and always taken for granted (such as chewing, etc.). Recent

studies however indicates the growing enthusiasm regarding central pattern

generators and these studies are quietly establishing the importance of making

such studies while delineating the possible consequences of such undertakings.

For example, it has been shown that central pattern generators modify the

behavior of Lymnea stagnalis by converting the pattern generators for feeding

into pattern generators of egg-laying. Also, some studies concern themselves in

localizing the central pattern generator, take note for example the findings that

suggests spinal circuitry in humans has the capability of generating locomotor-

like activity even when isolated from brain control, and that externally

controlled sustained electrical stimulation of the spinal cord can replace the

tonic drive generated by the brain.

Conclusion

Central pattern generators are neuronal structures that forms lattice-like

structure that accounts for the rhythmic or the usual physical functions such as

walking, swimming, chewing, etc. The complexity of these generators are evident

as they are widely distributed among the Earth’s inhabitants. The existence of

such generators has great implications in understanding human life. Whereas

some philosophers would say that we learn thru habit will be proven correct;

conversely, some existential philosophers that deny the possibility of such

dependence on structure might perhaps make a suggestion almost trying to

enact Leibniz’s monads.