Author response: A subcortical circuit linking the cerebellum to the basal ganglia engaged in vocal learning
Year: 2018
Type: peer-review
Abstract: Human infants learn to speak by imitating the speech of adults around them. Over time, they learn to coordinate movements of their vocal cords and breathing muscles to produce specific sounds. Juvenile songbirds go through a similar process while learning to sing. Fledglings mimic adult birds and each other as they learn to produce their own songs. Songbirds are therefore often used as a model for how the brain drives vocal learning – whether of speech or song. Circuits made up of similar brain regions support vocal learning in infants and in songbirds. These regions include areas of cortex, the outermost layer of the mammalian brain, as well as structures deep below the cortex. The latter include the basal ganglia, a set of structures that help mammals learn and perform fine motor skills. But there is one brain region that has been implicated in vocal learning in infants but not in songbirds. Known as the cerebellum or ‘little brain’, this structure also helps with planning and performing movements. Anatomical studies in songbirds suggest a connection between the cerebellum and song-related circuits. But a direct role in birdsong has never been shown. Pidoux et al. now demonstrate that stimulating the cerebellum in anaesthetized zebra finches activates basal ganglia neurons involved in song learning. This activation spreads through a song-related circuit to neurons controlling the vocal cords. Disrupting the cerebellum, by contrast, makes it harder for juvenile birds to imitate adult song. This is the first direct evidence for a role of the cerebellum in the acquisition of birdsong. Beyond vocal learning, the results shed light on the circuits that support motor learning more generally. They also suggest that we can use songbirds to study the cerebellum and its interactions with the basal ganglia. Abnormal interactions between these regions occur in movement disorders such as Parkinson's disease. Studying these interactions in the healthy mammalian brain should provide clues to the pathology behind these conditions.
Source: eLife
Language: English
Subfield: Developmental Biology
Domain: Life Sciences
Open Access status: gold
Estimated APC paid: $2,500
OpenAlex ID: W2986154396