Harnessing Hippocampal Stem Cells to Improve Mood and Cognition

Recent studies have implicated adult-born hippocampal neurons in pattern separation, a process by which similar experiences or events are transformed into discrete non-overlapping representations. Impaired pattern separation, Dr. Hen proposes, underlies the overgeneralization often seen in age-related memory impairments and in anxiety disorders. Dr. Hen will present evidence that strategies aimed at stimulating hippocampal neurogenesis result in improved pattern separation.

Illuminating Biology at the Nanoscale with Super-Resolution Florescence Microscopy

Stochastic optical reconstruction microscopy (STORM), breaks the diffraction limit on light microscopy by using selective activation of photo-switchable fluorescent probes to temporally separate the spatially overlapping images of individual molecules. This approach has allowed multicolor and 3-D imaging of living cells with nanometer-scale resolution, enabling discoveries of novel sub-cellular structures. In this talk, Prof. Zhuang will discuss her group’s development of STORM and its biological applications.

Online Social Systems

People spend hours a day interacting in online settings, ranging from social media sites to a broad range of digital communities designed for work, education and entertainment. Such systems are generally intended to elicit particular activities or forms of engagement, yet we have relatively little understanding of the resulting behaviors or of how system design may contribute to those behaviors. This talk will discuss work that aims to develop models of human behavior in online settings, both to inform system design but also to address fundamental questions in the social sciences.

The Origin of Specificity in Regulated Protein Degradation

One of the characteristic features of life — specificity — emerges in metabolism, information transfer from DNA to protein, embryology, immunology and virtually every other process. Its explanation on the molecular level is thermodynamic stability and structural complementarity. Yet one disturbing issue persists: the protein and nucleic acid sequences coding for that specificity are generally too small to distinguish actual partners from competitors. Similarly, protein degradation conveys specificity through very short sequences. The process is so kinetically complex that bulk kinetic experiments and a few molecular structures are insufficient to explain how specificity is achieved. Using single molecule kinetic measurements, we have deconvolved much of that specificity.