Research

The Meliza Lab studies the neural mechanisms of auditory perception in vocal communication. We work in two species of songbirds, the European starling (Sturnus vulgaris) and the zebra finch (Taeniopygia guttata). Starlings and finches live in large groups with dynamic social structures and use song to communicate individual identity, sexual fitness, and other social signals. Songbirds can learn to recognize hundreds of songs from different individuals under challenging and variable acoustic conditions. Understanding how their brains separate signal from noise and form coherent perceptual categories will give insight into similar processes underlying speech perception and other forms of perceptual learning.

Current research areas include:

Experience-dependent plasticity: A songbird's early experience hearing other members of its species shapes how its auditory system processes sound. This is analogous to the perceptual narrowing that occurs in humans during the first year of life, in which exposure to speech establishes the phonetic distinctions an infant is able to perceive. Deficits in this critical learning process may contribute to a wide range of communication disorders, including dyslexia. Using behavior, electrophysiology, immunohistochemistry, and gene-editing methods, we are investigating how the early acoustic environment influences the functional and physiological properties of cortical auditory circuits.

Internal models of auditory objects: Using behavioral and physiological methods, we examine how birds form internal models of vocal signals from experience, and how these models guide perception in the complex acoustic conditions animals encounter in natural social settings. Our goal is to identify how neural circuits create these models and employ them to reconstruct vocal signals that have been degraded by noise.

Data assimilation for dynamical models of auditory neurons and circuits: A major challenge in understanding how circuits like CM map the continuum of sensory stimuli onto discrete perceptual categories is the inherent nonlinearity of the computation and the neural systems that implement it. The formalism for biophysical models of neurons and circuits is well established, but better methods to infer the parameters of these nonlinear models from data are still needed. We are adapting dynamical systems methods originally developed for the study of chaotic physical systems to infer ionic currents in individual neurons, with the goal of using this approach to characterize neural diversity and to constrain circuit-level models of auditory processing.

April 2019: Hartwell Foundation Award

Dan received an Individual Biomedical Research Award from the Hartwell Foundation to use zebra finches as a model to improve early detection of auditory processing deficits. I'm recruiting a postdoc to work on this project, so check the opportunities page for details.

January 2019: Bjoring and Meliza, PLoS Comp Biol

A low-threshold potassium current enhances sparseness and reliability in a model of avian auditory cortex, by Margot Bjoring and C Daniel Meliza, is published in PLoS Computational Biology. Congrats Margot on your first paper in the lab!

December 2018: Andrew Chen, PhD

Andrew Chen successfully defended his PhD dissertation, Intrinsic Physiology and Experience-Dependent Plasticity of the Zebra Finch Caudal Mesopallium. He will be joining the staff at the Society for Neuroscience. Congratulations Andrew!!

April 2018: Margot Bjoring, Jefferson Scholars Foundation Fellow

Margot was selected as a Graduate Fellow by the Jefferson Scholars Foundation, a highly competitive award for PhD candidates who have exhibited a capacity for the highest levels of scholastic achievement. Congratulations Margot!

March 2018: Chen and Meliza, J Neurophys

Phasic and tonic cell types in the zebra finch auditory caudal mesopallium, by Andrew Chen and C Daniel Meliza, is published in the Journal of Neurophysiology. Congrats Andrew on your first paper in the lab!

December 2017: UVA Brain Institute Seed Grant

The Meliza, Beenhakker, and Deppmann labs were awarded a Transformative Neuroscience Pilot Grant by the University of Virginia Brain Institute to develop zebra finches as a model for dyslexia and other language-processing disorders.