A new type of specialized cells within the neural circuitry of songbirds can trigger complex learning, according to researchers at the Vollum Institute, Oregon Health and Science University. The type of cells resembles a type of neural cell in the cortex of the human brain associated with the development of fine motor skills.
In a paper published the journal Nature Communications, the researchers have revealed that a set of genes expressed by a particular group of neurons modulate sodium ion channel proteins. The channels generate electrical signals that are used for communication between neurons in the nervous system.
Songbirds sing by firing repetitive spikes, called action potentials, at extremely high frequencies and speeds, with each spike barely lasting 0.2 milliseconds (a millisecond is one-thousandth of a second).
It is these properties that make a song distinct and precise, so that a female can choose which bird she wants to mate with,” said Henrique von Gersdorff, co-author of the study and a scientist at the Vollum Institute, Oregon Health and Science University.
Researchers have also discovered new ways to examine how motor functions develop in humans. A songbird’s neuronal assemblage is similar to that of a human brain’s Betz cells.
The brain’s primary motor cortex contains Betz cells, which are among the largest cells in humans. Songbird cells have thick and long axons that fire electrical signals at high velocities and frequencies. It is long thought that Betz cells are crucial to learning fine motor skills, such as playing a complex musical instrument or driving a car.
“Think of a piano player,” Claudio Mello, co-author of the paper and a professor of behavioural neuroscience at the Oregon Health and Science University School of Medicine, said in a press release. “They’re thinking so quick, they have to rely on memories and actions that are learned and stored. Playing the guitar is the same thing.”