Research Interests
Why Study a Songbird?
Much like a human toddler learning language, young songbirds learn to imitate the vocal patterns of an adult during a sensitive period of development. Also like humans, songbird vocal patterns are controlled by a forebrain network that includes pre-motor, striatal, and auditory pathways dedicated to processing vocal sounds and gestures. The striking behavioral and neural similarities between songbird vocal learning and human language learning suggest a process of convergent evolution, making songbirds an ideal animal model to study the neural and molecular mechanisms that underlie the development of human speech. In my laboratory we investigate the behavioral, cellular, and molecular processes that enable the songbird brain to learn and generate vocal sounds, a property once thought to be uniquely human.
Song Behavior
High Resolution Measurement of an Abundant Vocal Signal
Although few of us take the time to count them all, humans produce several thousand words per day, a corpus of behavior characterized by complex variation in phonology and syntax. Songbirds do something similar. Adult songbirds produce their learned vocal patterns several hundred times each day, resulting in the production of several thousand song syllables each day. We are currently engaged in the development of a high resolution measurement strategy capable of capturing the variation in phonology and syntax inherent in whole days of recorded birdsong. Key collaborators and colleagues on this project are Dr. Richard Bertram (FSU Department of Mathematics) and Dr. Wei Wu (FSU Department of Statistics).
The Brain/Environment Interface
Gene Expression That Enables Neural Plasticity and Learning
In addition to remarkable vocal skills, another source of our enthusiasm for the songbird is the prominent anatomy of the neural circuit that controls learned song. The discrete anatomy of the song control system makes it an ideal place to search for the neuronal gene products that form the dynamic interface between brain and environment.
How Does the Song Control System Work?
Towards a Theory of Functional Brain Architecture
One of the great remaining challenges in neuroscience is the construction of a general theory of brain function. How, exactly, does it all work? While humility demands that we acknowledge the awesome magnitude of this task, ongoing experiments designed to delineate the functional anatomy of the song control system promise significant advances toward the development of such a theory.
Selected Publications
- Wu, W., J.A. Thompson, R. Bertram and F. Johnson. (2008). A statistical method for quantifying songbird phonology and syntax. The Journal of Neuroscience Methods, 174, 147-154.
- Thompson, J.A., W. Wu, R. Bertram, and F. Johnson (2007) Auditory- dependent vocal recovery in adult male zebra finches is facilitated by lesion of a forebrain pathway that includes the basal ganglia. The Journal of Neuroscience, 27:12308-20.
- Thompson, J. A. and F. Johnson (2007) HVC microlesions do not destabilize the vocal patterns of adult male zebra finches with prior ablation of LMAN. Developmental Neurobiology, 67:205-18.
- Johnson, F., and O. Whitney (2005) Singing-driven gene expression in the developing songbird brain. Physiology and Behavior, 86:390-8.
- Whitney, O., and F. Johnson (2005) Motor-induced transcription but sensory-regulated translation of ZENK in socially interactive songbirds. The Journal of Neurobiology, 65:251-9.
- Whitney, O., K. Soderstrom, and F. Johnson. (2003). CB1 cannabinoid receptor activation inhibits a neural correlate of song recognition in an auditory/perceptual region of the zebra finch telencephalon. Journal of Neurobiology, 56, 266-74.