Research in the Brainard laboratory focuses primarily on the question of how genetics and experience, particularly during early life, shapes the functioning of the nervous system using a combination of behavioral and neurophysiological techniques to investigate the mechanisms underlying vocal production and learning in songbirds. 


Sensory-Motor Learning

The study of song learning offers the advantages of a well described behavior that exhibits a variety of general features of learning, and that is subserved by a discrete and extensively investigated set of brain regions. Because many species of songbirds breed well in captivity and develop rapidly, they are well suited for studying processes of developmental plasticity. Song learning proceeds in two stages. First, during a period of sensory learning, young birds listen to and memorize the song of an adult 'tutor'. Then, during a period of sensorimotor learning, they use auditory feedback to gradually refine their own initially rambling vocalizations so that they progressively resemble the previously memorized tutor song. Normal song learning requires appropriate experience during a sensitive period in early development, although recent studies have shown that auditory feedback also contributes to the adult maintenance of precisely calibrated vocal output. These features make song learning a useful model for studying the mechanisms that contribute to vertebrate sensory and sensorimotor learning in general, and to certain components of human language learning in particular; speech acquisition exhibits strikingly similar requirements for memorization and vocal practice during early development and for maintained auditory feedback throughout life.


Motor Control and Coordination 

The vocal behaviors of songbirds also provide powerful models for studying how the brain produces complex sequences of motor actions. In Bengalese finches, song is formed by stringing together short, discrete vocalizations known as syllables with short gaps of silence in between. The transition from some syllables to the next is seemingly deterministic in some cases (syllable A is always followed by syllable B) and probabilistic in others (syllable C is followed by syllable D 60% of the time and syllable E 40% of the time). By understanding the neural dynamics which lead to these variable transitions, we can begin to unravel the way in which brains complete action sequences in general.

Additionally, the motor programs driving vocalizations must be coordinated across different brain regions and with other ongoing behaviors such as breathing. By studying how ongoing respiratory dynamics are integrated into vocalizations, we aim to understand how the brain coordinates such important behaviors as breathing and vocalizations.


Genetics and Environment Interactions

The neural circuits that give rise to behavior are shaped by complex interactions of genetics and environment. To study these interactions in the lab, we control the genetic background and the experience of our songbirds and measure the impact on its song. For instance, we have found that tailoring instruction to the genetic background of a given bird yields better learning outcomes (Mets and Brainard, 2019). Our current work seeks to elucidate how genetic predispositions and environmental influences are reflected in innate versus plastic neural systems. We also seek to expand our understanding of how the vocal behavior of female songbirds (who produce short calls but not songs) is shaped by genetic and environmental factors.


Cell types

We are interested in the molecular and cellular mechanisms that underlie song learning in juveniles and song adaptation in adults and how these processes relate to similar mechanisms in the mammalian brain. We are also investigating the neuronal repertoires of songbirds and mammals at cellular resolution to try to understand what neural circuit elements are conserved across species and which represent evolutionary innovations that may contribute to species-specific differences in neural function and behavior.