New research reveals that specialized cells that trigger complex learning in songbirds bears a striking resemblance to a type of neural cell that develops fine motor skills in the human brain.
“These are the properties you need if you want to have a male song that’s precise and distinct so the female can choose which bird she wants to mate with,” said co-senior author Henrique von Gersdorff, Ph.D., senior scientist the OHSU Vollum Institute. “You need a highly specialized brain to produce this.” Benjamin Zemel, Ph.D., a postdoctoral fellow at OHSU, is lead author and conducted most of the challenging electrophysiology work involved in using thin brain slices and single cell recording.
From songbird to human
The study reveals that a particular group of neurons are associated with the electrical signals used for communication between cells in the nervous system.
Researchers say the group of neurons and ion channels involved in the male zebra finch’s singing closely resembles a similar group of neurons known as Betz cells in the primary motor cortex of the human brain. Among the largest known brain cells in humans, Betz cells have long and thick axons that can create spikes at very high velocities and frequencies. As such, they are thought to be important for fine motor skills involving hands, feet, fingers and wrists.
“Think of a piano player,” said co-senior author Claudio Mello, M.D., Ph.D., professor of behavioral neuroscience in the OHSU School of Medicine. “They’re thinking so fast, they have to rely on memories and actions that are learned and stored. Playing the guitar is the same thing.”
Learning fine motor skills
The study published today is a result of an informal conversation that initially occurred over lunch in the Mackenzie Hall Café on OHSU’s Marquam Hill campus.
“Something remarkable was happening in a period of just a few days,” said von Gersdorff, an expert in electrophysiology and the biophysics of neurons. “I said, this is exactly the protein we’ve been studying in the rodent auditory system. It promotes high frequency spiking.”
Mello said the new study deepens scientific understanding of the mechanism involved in learning fine motor skills. “This is a very important model, and we think this new study has broad potential,” he said.
It also suggests mechanisms that may be involved when the connection goes awry. Von Gersdorff said it’s possible that some gene mutations affecting these Betz cells may cause relatively mild effects such as stuttering, which can be overcome by learning, whereas other mutations could have more pronounced effects, such as those involved in progressive disorders such as amyotrophic lateral sclerosis, or ALS.
This exciting research helps us understand what happens in the brain when we use our fine motor skills. It also shows the importance of repeated practice for learning fine motor skills and it reminds us again that speech movements and body movements also depend on fine motor learning. Daily NeuroNet exercises include fine-motor skill development for balance (focused attention), speech and handwriting. Daily speech practice also includes academic learning for math fact retrieval, reading decoding and alphabet knowledge.