Songbirds’ Learning Hub in Brain Offers Insight into Motor Control
UCSF finding could lead to strategy for treating disorders such as Parkinson’s disease
To learn its signature melody, the male songbird uses a trial-and-error process to mimic the song of its father, singing the tune over and over again, hundreds of times a day, making subtle changes in the pitch of the notes. For the male Bengalese finch, this rigorous training process begins around the age of 40 days and is completed about day 90, just as he becomes sexually mature and ready to use his song to woo females.
To accomplish this feat, the finch’s brain must receive and process large quantities of information about its performance and use that data to precisely control the complex vocal actions that allow it to modify the pitch and pattern of its song.
Now, scientists at UCSF have shown that a key brain structure acts as a learning hub, receiving information from other regions of the brain and figuring out how to use that information to improve its song, even when it’s not directly controlling the action. These insights may help scientists figure out new ways to treat neurological disorders that impair movement such as Huntington’s disease and Parkinson’s disease.
The research is reported as an advanced online publication on May 20, 2012 by the journal Nature, and will appear at a later date in the journal’s print edition.
Years of research conducted in the lab of Michael Brainard, PhD, an associate professor of physiology at UCSF, has shown that adult finches can keep track of slight differences in the individual “syllables,” or notes, they play and hear, and make mental computations that allow them to alter the pitch.
For previous experiments, Brainard and his colleagues developed a training process that induced adult finches to calibrate their song. They created a computer program that could recognize the pitch of every syllable the bird sang. The computer also delivered a sound the birds didn’t like — a kind of white noise — at the very moment they uttered a specific note. Within a few hours, the finches learned to alter the pitch of that syllable to avoid hearing the unpleasant sound.
In the new research, the UCSF neuroscientists used their technology to investigate how the learning process is controlled by the brain. A prevailing theory suggests that new learning is controlled by a “smart” brain structure called the basal ganglia, a cluster of interconnected brain regions involved in motor control and learning.
“It’s the first place where the brain is putting two and two together,” said Jonathan Charlesworth, a recent graduate of UCSF’s neuroscience PhD program and the first author of the new paper. “If you remove the basal ganglia in a bird that hasn’t yet learned to sing, it will never learn to do so.”
Once a basic, frequently repeated skill such as typing, singing the same song or shooting a basketball from the free-throw line is learned, the theory suggests, control of that activity is carried out by the motor pathway, the part of the nervous system that transmits signals from the brain to muscles. But for the basic routine to change—for a player to shoot from another spot on the basketball court or a bird to sing at a different pitch—the basal ganglia must again get involved, providing feedback that allows learning based on trial and error, the theory suggests.
What remained unclear is what makes the basal ganglia so “smart” and enables them to support such detailed trial-and-error learning. Was it something to do with their structure? Or were they getting information from elsewhere?
The scientists sought to answer this question by blocking the output of a key basal ganglia circuit while training male finches to alter their song using the white-noise blasts. As long as the basal ganglia were kept from sending signals to the motor pathway, the finches didn’t change their tune or show signs of learning. But when Brainard’s team stopped blocking the basal ganglia, something surprising happened: the finches immediately changed the pitch of their song, with no additional practice.
“It’s as if a golfer went to the driving range and was terrible, hitting the ball into the trees all day and not getting any better,” said Charlesworth. “Then, at the end of the day, you throw a switch and all of a sudden you’re hitting the fairway like you’re Tiger Woods.”
Normally, you’d expect improvement in skill performance like this to take time as the basal ganglia evaluates information, makes changes and gets new feedback, Brainard said.
“The surprise here is that the basal ganglia can pay attention, observe what other motor structures are doing and get information even when they aren’t involved in motor control,” Brainard said. “They covertly learned how to improve skill performance and this explains how they did it.”
These findings suggest that the basal ganglia’s “smartness” is due in large part to the steady flow of information they receive about the commands of other motor structures. It also portrays the basal ganglia as far more versatile than previously understood, able to learn how to calibrate fine-motor skills by acting as a specialized hub that receives information from various parts of the brain and responds to that information with new directives.
The findings also support the notion that problems in the basal ganglia circuit’s ability to receive information and learn from it may help trigger the movement disorders that are symptoms of Huntington’s and Parkinson’s, Brainard said.
Timothy Warren, another PhD graduate working in Brainard’s lab, was the paper’s third author.
Funding support for the research came from the National Institutes of Health and the National Science Foundation.
UCSF is a leading university dedicated to promoting health worldwide through advanced biomedical research, graduate-level education in the life sciences and health professions, and excellence in patient care.
Contact: Jennifer O’Brien
jennifer.obrien@ucsf.edu
415-502-6397
University of California – San Francisco
The Color of a Robin’s Eggs Determines Parental Care
A male robin will be more diligent in caring for its young if the eggs its mate lays are a brighter shade of blue.
Queen’s University biology professor Bob Montgomerie has been studying robins on and off for 25 years and has a particular fascination with the bright blue colour of their eggs. To test a theory on the purpose of bright egg colouration, Dr. Montgomerie and MSc student Philina English, working at the Queen’s University Biological Station (QUBS) and other sites around Kingston, replaced the real eggs in robins’ nests with artificial eggs of different shades of blue.
Just before the real eggs would have hatched, the researchers replaced the artificial eggs with baby robins.
“We were testing the idea males can use egg colour as a signal of the quality and health of their mate, and that healthy mates create better babies,” says Dr. Montgomerie, whose research focuses on sexual selection and parental care in birds. “Sure enough, males whose nests contained the brightest blue eggs fed their newly-hatched babies twice as much.”
The blue colour in robin eggs is due to biliverdin, a pigment deposited on the eggshell when the female lays the eggs. There is some evidence that higher biliverdin levels indicate a healthier female and brighter blue eggs. Eggs laid by a healthier female seemed to encourage males to take more interest in their young.
The paper was published in Behavioral Ecology and Sociobiology.
Contact: Anne Craig
anne.craig@queensu.ca
613-533-2877
Queen’s University
Barn Owls that Know No Borders
From the BBC, May 18, 2012
Farmers from Israel and Jordan have been using barn owls instead of pesticides to deal with mice and rats for the last 10 years as part of a joint conservation venture called Project Barn Owl.
And with the arrival of new chicks, it seems as if the barn owls have been making use of some of the thousands of nesting boxes which had been placed in the fields of each country.
As reported by Tom Santorelli
Comparing Apples to Oranges – A Catbird’s Point of View
Claire Horvath from Mother Nature’s Store in Columbia MD offers up her simple “research” project results. Here’s Claire’s most recent email update:
Just learned something new…
The catbirds seem to really prefer apples to oranges! The oranges we hang to try to attract the orioles (not yet, but we keep at it!), the catbirds leave. But they can go through more than 2 apples a day!
Just wanted you to know! Oh and this is one of the best videos I have ever seen about the catbird and how he mimics. Really, really worth a minute!
Learning Bird Songs: The “Old Fashioned Way” is Still Best
I recently completed the Wissahickon Valley Watershed Birdathon. This is a two day birding marathon in which teams from the Philadelphia area try to one-up each other to see or hear more bird species than the other teams. We found that sometimes it’s easier to hear a bird’s song, even though you can’t easily see the bird. Let’s face it – there’s wind in the trees, making movement that looks like a bird, and those pesky leaves – all making it really difficult to see those little guys.
With regard to hearing bird calls, the tide has definitely turned on available tools to help in the field. With smartphones becoming more and more readily available, bird-related apps are gaining popularity. This got me thinking about how one learns bird calls, songs, sounds and so on. What tools do you need, and what is the best way to learn? In discussing it, we all agreed that, though phone apps are nifty to have, and even downright useful, they can’t replace really getting to know the calls pretty well first. A birding app, like the iBird Pro 2
There are a number of decent CD’s available for learning sounds. Since I live in the Eastern United States, I used A Field Guide to Bird Songs: Eastern and Central North America , which is designed to go along with the Peterson Bird Guides. There is also a western version, A Field Guide to Western Bird Songs: Western North America. These CD’s arrange the birds by similar sounding calls, which was helpful. (of course, if I ever spend much time in the west, I’ll have to learn a bunch of new ones!)
Another person on our team used the Field Guide To Bird Songs East by Stokes
My personal recommendation would be to purchase two different CD types – that is, both of the recommended sets above or two differing other titles. If you have just one set, you get used to the birds being “fed” to you in a certain way. For example, all the woodpecker species together. But that’s not how it is in nature. You hear one, but not the others. By listening to a variety, you don’t become so “used to” hearing the sounds the same way.
Team Kestrel, as we are called, consists of three people – myself and two others – who know most bird calls (or chatters or songs). We all learned the long way, by listening to recorded bird sounds and getting out into the outdoors to hear them as well. This is, in my opinion, still the best way to become thoroughly familiar with the various bird calls. This year was the first time that we had my smartphone out in the field with us to help confirm any of those ornery “sound alikes”. That is, cases in which we may have had some disagreement, we used the iBird Pro 2
The Take Away:
Birding apps are fun, cool and inexpensive, but can’t replace the patience of listening to other recorded media and good old fashioned trudging through fields, forests, streams and waterways.
More Wind Power With Fewer Bird Deaths
The Santa Fe New Mexican – In hopes of increasing wind energy production in New Mexico while protecting wildlife and habitat, a coalition of energy companies, conservation groups and government agencies have come up with recommendations.
The group this week launched a website to list the “best management practices” for designing and siting wind facilities while protecting bats, raptors and other birds. The coalition says its recommendations are based on science but aren’t binding on any of the energy companies operating in the state.
The New Mexico Wind and Wildlife Collaborative involves eight energy companies, seven conservation groups and several agencies such as the New Mexico Department of Game and Fish and the U.S. Fish and Wildlife Service. Public Service Company of New Mexico, First Wind, Audubon New Mexico and Hawks Aloft are among the groups that met over the last two years to hammer out recommendations for wind farms.
“We were trying to create a process where birds would be considered in siting not just wind facilities, but all renewable energy sources such as solar,” said Christopher Ratay of Playa Lakes Joint Venture, a bird conservation group that helped facilitate the meetings. “Even though there are no state or federal regulations governing it, wind facilities want to try and avoid problems.”
Industry and conservation groups had to understand each other’s positions to reach agreements, Ratay said. Industry needed to make sure it can build wind facilities and transmit the electricity at a reasonable cost to consumers. Conservationists want wildlife and habitat protected.
While wind energy is considered a “green” renewable source of electricity, the facilities still can harm wildlife and habitat. The height of wind turbines, the design and length of the blades and the location of the towers can all impact birds and bats. Wind turbine pads and the roads to reach them fragment wildlife habitat, a special problem if the facilities are located in an area with threatened and endangered species.
Newer wind turbines and blades kill fewer birds than older ones. Still, if wind turbines are placed in the flight path of endangered raptors and migratory birds, the deaths of even a few create a problem, according to biologists.
Industry needs to site wind facilities where there’s plenty of wind and transmission lines are close.
“We wanted to make sure any guidelines put out would be achievable but would satisfy all the parties,” said Matt Desmond of First Wind, a wind-energy development company.
The group developed best management practices for 12 wildlife species and for critical habitat such as playas.
What remains to be seen is how many wind-energy companies will follow the recommendations.
For more information about the collaboration and to see best management practices, visit www.pljv.org/windandwildlife/nm/nmwwc.php.
Contact Staci Matlock at 986-3055or smatlock@sfnewmexican.com.