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Welcome to my page
I’m a graduate student in the lab of Fernando Nottebohm at the Rockefeller University in NYC. We study, amongst other things, the neural mechanisms for vocal learning and the intricacies of adult neurogenesis using several species of songbird. I am interested in the brain’s capacity for repair, especially repair that can restore function. My thesis project uses the well-mapped song system of the zebra finch and a cool technique to explore the potential role of adult-born neurons in functional brain repair.
News
The Rockefeller University's Summer Neuroscience Program is an intense 2-week summer school for students from New York City public schools. We take around 15 junior or senior students and teach them all the wonderful and wacky things that science has discovered about the brain in an attempt to get them psyched about science. 2010 is the third year that the program will run and so far it has been a great success for both the students and the teachers involved. The new website is up and running and we are now accepting nominations for the 2011 class. Check it out!
Transgenic songbirds? No problem! Thanks to the recent efforts of Dr Agate in the Nottebohm lab the molecular toolkit available to songbird researchers has just expanded.
My science
Why songbirds?
The connected song system just pops right out!
Firstly, they are awesome. They are one of a few species, ourselves included, that are capable of vocal learning. And by vocal learning I mean the ability to modify one’s vocalizations based on auditory experience. This process is vital for human speech and if our brains weren’t capable of such a feat, the world would be a very different place. Other mammals that can perform this kind of learning include bats, dolphins, whales, seals and most recently documented elephants (including one messed up African elephant who tries to talk to the park ranger’s truck).
Vocal learning allows us to take in sounds produced by others of our species and match those sounds in order to communicate. It is not surprising that this complex behavior only seems to have arisen in social species. Songbirds may not be capable of producing language as we humans know it, but there are many parallels between the way we learn to speak and the way a young bird learns to sing. Both processes require exposure to the desired sounds from a tutor or parent during a critical period in development and social cues from that instructor are important to guide learning of the correct sounds. Experimenting with the vocal organ is also a key step in the process; babies babble and so do baby birds. We’ve come a long way to understanding the neural circuits involved in song learning. There is a discreet set of connected nuclei that appears to be dedicated to the task. While these circuits are not identical to those in the human brain, there are likely to be many similarities in the way neurons work together to master control of the vocal machinery. We can’t poke and prod the brains of our infant children, so doing it with songbirds might just be the next best thing.
So songbirds are capable of some pretty fantastic behaviors, but why use them to study brain repair? Well another thing that makes these little critters pretty good models for neuro-nerds is that their brains continue to generate new neurons throughout adulthood. This is not a phenomenon unique to birds. In fact, despite the old dogma that we are born with all the brain cells we will ever have, the production of new neurons has been documented in all vertebrate species tested, including humans. The difference is that in mammals, the production of new neurons in the adult brain (termed adult neurogenesis) is restricted to a few discreet brain regions whereas in birds, neuron production is more widespread and these new neurons migrate all over the telencephalon. Despite a great deal of research into the matter, the functional role of these new brains cells remains unclear. Their incorporation into the mammalian hippocampus, the center for learning, and also seasonal peaks in neurogenesis in adult canaries during the time of the year when they are learning new song syllables has led to the tantalizing possibility that new neurons provide the platform for laying down new memories. However, showing a causal link between adult neurogenesis and learning is proving difficult, in part because exactly how the mammalian hippocampus participates in learning and memory is not well understood. Disrupting normal neuron production in rodents has been done by many labs but the effects on learning have been conflicting and unclear.
This is where the songbird system steps up. As I mentioned above, the song system is a discreet set of well-mapped nuclei solely dedicated to the task of song production and perception. Adultborn neurons integrate directly into the adult song system and make connections in the motor pathway for song production. Since birdsong is a stereotypic and easily quantifiable behavior, we can use singing behavior as a readout of the system as it receives the new neuronal inputs. My current research focuses on creating neurodegeneration in the song motor pathway of adult male zebra finches, which causes a profound behavioral deficit, and then following closely the song and the neuroanatomy as new neurons come in to repopulate the network. The fact that our brains are capable of producing new cells just like other tissues in the body has exciting implications for the treatment of brain damage and neurodegeneration; conditions that can destroy the lives of suffers and their families. But first we must show that adultborn neurons have the capacity to integrate into damaged pathway in a way that leads to functional recovery. This is what I’m hoping to do in the zebra finch song system…..so watch this space!
Scientific Posters
 Walton C, Alvarez-Borda B & Nottebohm F. Presented at the 2008 Gordon Research Conference in Neuroethology: Behavior, Evolution & Neurobiology, Oxford, UK. |  Walton C, Pariser E & Nottebohm F. Presented at the 2009 Meeting of the Society of Neuroscience, Chicago, IL |
OneSci Honors
| An apple for being such an active new user. Keep up the good work! |