A song system, also known as a song control system (SCS), is a series of discrete brain nuclei involved in
song production and
vocal learning Vocal learning is the ability to modify acoustic and syntactic sounds, acquire new sounds via imitation, and produce vocalizations. "Vocalizations" in this case refers only to sounds generated by the vocal organ (mammalian larynx or avian syrinx) a ...
in
songbird
A songbird is a bird belonging to the suborder Passeri of the perching birds (Passeriformes). Another name that is sometimes seen as the scientific or vernacular name is Oscines, from Latin ''oscen'', "songbird". The Passeriformes contains 5,00 ...
s. It was first observed by
Fernando Nottebohm
Fernando Nottebohm (born 1940 in Buenos Aires) is a neuroscientist. He serves as the Dorothea L. Leonhardt Professor at Rockefeller University, as well as being head of the Laboratory of Animal Behavior and director of the Field Research Center fo ...
in 1976 in a paper titled "Central control of song in the canary, ''Serinus canarius''", published in the ''Journal of Comparative Neurology''.
Operation
Based on
lesion
A lesion is any damage or abnormal change in the tissue of an organism, usually caused by injury or diseases. The term ''Lesion'' is derived from the Latin meaning "injury". Lesions may occur in both plants and animals.
Types
There is no de ...
studies in the
zebra finch
The zebra finches are two species of estrildid finch in the genus ''Taeniopygia'' found in Australia and Indonesia. They are seed-eaters that travel in large flocks. Species
The species are:
Previously, both species were classified as ...
, the song system can be broken into two general pathways. The direct/descending motor pathway is both necessary and sufficient for normal song production, while the anterior
forebrain
In the anatomy of the brain of vertebrates, the forebrain or prosencephalon is the rostral (forward-most) portion of the brain. The forebrain controls body temperature, reproductive functions, eating, sleeping, and the display of emotions.
Ve ...
pathway (AFP) is necessary for song learning but not production.
Juvenile birds who have not yet fully learned their songs and that have lesions of the AFP never learn to make normal songs. Adult birds who experience these same lesions continue to sing normally for some time. The song system is
sexually dimorphic
Sexual dimorphism is the condition where sexes of the same species exhibit different Morphology (biology), morphological characteristics, including characteristics not directly involved in reproduction. The condition occurs in most dioecy, di ...
in many species of songbirds, especially in species in which the male primarily sings.
System model
The song system has emerged as leading model of adult
neural plasticity
Neuroplasticity, also known as neural plasticity or just plasticity, is the ability of neural networks in the brain to change through growth and reorganization. Neuroplasticity refers to the brain's ability to reorganize and rewire its neural ...
. The song system is the first
neural circuit in which it was conclusively demonstrated that
newly generated neurons are incorporated into the brains of adults
vertebrates
Vertebrates () are animals with a vertebral column (backbone or spine), and a cranium, or skull. The vertebral column surrounds and protects the spinal cord, while the cranium protects the brain.
The vertebrates make up the subphylum Vertebra ...
. Some seasonally-breeding songbird brains vary in volume,
neuron
A neuron (American English), neurone (British English), or nerve cell, is an membrane potential#Cell excitability, excitable cell (biology), cell that fires electric signals called action potentials across a neural network (biology), neural net ...
number, and density depending on the time of year, and these changes in the brain are driven by changes in circulating levels of
testosterone
Testosterone is the primary male sex hormone and androgen in Male, males. In humans, testosterone plays a key role in the development of Male reproductive system, male reproductive tissues such as testicles and prostate, as well as promoting se ...
.
External links
Fernando Nottebohm's "Central control of song in the canary, ''Serinus canarius''"
See also
*
Bird vocalization
Bird vocalization includes both bird calls and bird songs. In non-technical use, bird songs (often simply ''birdsong'') are the bird sounds that are melodious to the human ear. In ornithology and birding, songs (relatively complex vocalizatio ...
*
Vocal learning Vocal learning is the ability to modify acoustic and syntactic sounds, acquire new sounds via imitation, and produce vocalizations. "Vocalizations" in this case refers only to sounds generated by the vocal organ (mammalian larynx or avian syrinx) a ...
References
{{Reflist
Animal nervous system