Unless otherwise noted, Spring 2012 lectures will be held the second Wednesday of each month at 4:00 PM in Room 5235 MSC.

September 13th - Optophysiological Studies of the Mammalian Olfactory Bulb

Venkatesh Murthy
Department of Molecular and Cellular Biology
Harvard University

Mice and rats use around 1000 types of odorant receptors to probe chemical space in the main olfactory system. Receptor neurons in the nose project their axons to the olfactory bulb and form anatomical units called glomeruli. Odor information is then processed by the postsynaptic circuitry in bulb, which includes feedback projections from cortical areas and brainstem neuromodulatory centers. The modular organization, the superficial location and the sensory nature of the olfactory bulb allow us to study many aspects of brain function at subcellular resolution in living animals. My research group has used different forms of optical microscopy as well as optogenetics to investigate how odors are represented in the olfactory bulb, how this representation is transformed by local circuits as well as by top-down influences from the brain. In this talk, I will present results of some recent and ongoing studies from my laboratory.

November 8th - Functional Molecular Imaging in the Brain

Alan Jasanoff
McGovern Institute for Brain Research
Department of Biological Engineering

Functional magnetic resonance imaging (fMRI) with contrast agents sensitive to neural activity could have great impact in neuroscience by combining noninvasive whole-brain coverage with molecular-level specificity for neuronal events. Our research group is developing molecular fMRI approaches based on MRI-detectable sensors we have designed to monitor intra- and extracellular signalling events in the nervous system. Our sensors are built on a variety of chemical platforms, ranging from small molecules to nanoparticles. Protein-based contrast agents are of particular interest to us because of the possibility of gene-based brain delivery strategies and the availability of powerful protein engineering techniques. Here we describe the chemistry and bioengineering of several MRI sensors for neural activity, as well as the first efforts in our laboratory to perform functional neuroimaging with molecular specificity in living brains.

December 13th - Biomarkers for the Early Detection of Alzheimer's Disease
Note Location (5235 MSC)

Barbara Bendlin
Department of Medicine
University of Wisconsin-Madison

Alzheimer’s disease (AD) affects more than 5.3 million people in the US and millions more worldwide. Age is the primary risk factor for AD and as the population ages a dramatic upsurge in AD cases is expected in the coming decades (up to an estimated 11-16 million cases by 2050). Without intervention, AD will exert a devastating human toll and likely will bankrupt federal healthcare programs. Consequently, it is imperative that we recognize early markers of the disease, facilitate the development of new treatments by characterizing early brain changes in AD, and establish markers of treatment efficacy for use in clinical trials. Our laboratory is focused on understanding the earliest brain changes in AD by studying people who are still healthy but have increased risk of developing AD due to parental family history, genotype and vascular risk factors. This lecture will outline our recent findings from studies of people at risk for AD, and summarize the utility of brain imaging, in particular white matter imaging, for early AD detection.

February 1st - What Are Ca2+ Permeable Glutamate Receptors Doing in Plants?

Edgar Spalding
Department of Botany
University of Wisconsin-Madison

April 11th - Anticipating that Bad Things Will Happen: Anxiety in the Human Brain

Jack Nitschke
Departments of Psychiatry and Psychology
University of Wisconsin-Madison

Anxiety disorders cause untold personal suffering and exact a large societal and economic burden. The debilitating consequences of anxiety disorders stem not from heightened responsivity to the occurrence of adverse events, but rather from worry and anticipation about possible future adversity. Our research program began by studying healthy volunteers in order to investigate the neural mechanisms of anticipatory processes that serve adaptive functions when executed at a level commensurate with the likelihood and severity of threat. Our attention then turned to the deleterious consequences that anticipatory processing can have when conducted excessively relative to the objective likelihood and severity of threat. Key brain areas implicated include the amygdala, insula, and anterior cingulate cortex. Building on these fMRI findings isolating activation differences in discrete brain regions, our more recent work has utilized a range of other MRI methodologies--fMRI-based functional connectivity, DTI-based structural connectivity, and voxel-based morphometry--to more comprehensively assess circuitry alterations in anxiety disorders. Finally, we have begun treatment studies with the goal of identifying brain measures that can be used in guiding treatment decisions on an individualized case basis.

May 9th - Dissecting Membrane Trafficking Pathways by Electron Tomography

Marisa Otegui
Department of Botany
University of Wisconsin-Madison

Plant cells exhibit highly dynamic protein and membrane trafficking pathways. Many key protein and membrane sorting events occur in very small compartments or even in subdomains within an organelle, which makes their visualization by light microscopy very challenging. To analyze the endosomal sorting of plasma membrane proteins for degradation and the vacuolar transport of storage proteins in seeds, we perform dual-axis electron tomography of high-pressure frozen/freeze-substituted plant material. We obtain 3D reconstructions of large areas of the cells containing organelles of interest and subject them to segmentation, model calculation, and quantitative analysis. Electron tomography in combination with structural pattern recognition of known macromolecular complexes and/or immunogold labeling allow for the correlation between structure and biochemical composition. Several examples on how these imaging approaches have been applied to the understanding of plant trafficking pathways will be discussed.