Assistant Professor Myriam Heiman

Title: Cell Type-Specific Profiling and Genetic Screening Studies of Huntington's Disease

Abstract: Huntington’s disease (HD) is the most common inherited neurodegenerative disorder, and is characterized by early and most dramatic loss of neurons in the caudate and putamen as well as a debilitating triad of cognitive, motor, and psychiatric symptoms.  The huntingtin gene was first linked to HD over twenty years ago, yet to date there is neither a precise molecular explanation for the cell loss that is seen in human patients, nor a curative therapeutic.  In my talk, I will describe our efforts over the last few years to advance our understanding of the mechanistic basis of HD.  We have combined the use of cell type-specific gene expression profiling with in vivo genetic screening to reveal transcriptional pathways perturbed by mutant Huntingtin protein, as well as the genes that help neurons survive in HD.

Assisant Professor Josh McDermott

Title: Environmental Sound Statistics and Auditory Scene Analysis

Abstract: When we listen, the sound reaching our ears comes directly from a source as well as indirectly via reflections known as reverberation. Reverberation profoundly distorts the sound from a source, but in doing so provides information about the spaces we occupy. This talk will explore the ability of human listeners to separate the contributions of reverberation and of a sound’s source to the signal entering the ears. We find that everyday environments exhibit strong statistical regularities, and that we rely on these regularities to analyze sound. As a consequence, human listeners can perceptually separate source signals from reverberation, but are severely impaired when reverberation characteristics deviate from those of real-world environments.

Assisant Professor Mark Harnett

Title: Biophysics of computation in mammalian neural circuits

Abstract: The brain exhibits incredible computational power, processing staggering amounts of information from the external world to adaptively guide behavior. The biological basis for how this occurs in the mammalian nervous system - what forms computations take in neural circuits and the cellular substrates underlying them - is largely unknown. Research in our lab focuses on the elementary input-output operations carried out in single neurons as building blocks for circuit-level computations. We employ a combination of optical and electrophysiological experimentation in acute brain slices and behaving rodents to understand how neurons use biophysical processes at the level of synapses and dendrites to support the circuit computations that ultimately create complex, internal representations of the environment and past experiences. The goals of our research are first to distill out fundamental computational principles of neural circuits to inform new, biophysically-realistic neural network models, and second to provide detailed mechanistic insight towards development of therapeutic interventions for disorders of cognition.