Physical therapy is a grueling process usually met with limited gains and quickly reached plateaus of recovery. Many robotic devices have been incorporated into the clinic because they provide a highly repeatable and accurate training experience while lessening the burden of the therapist. Unfortunately one of the more popular devices, the Lokomat robotic gait trainer, has fallen out of favor because early studies on the effectiveness of the device showed mixed results. This is no reason to stop using the tool, but reason to learn how to use the tool better. Standard robotic gait training therapy involves guiding the injured limbs through a healthy stepping pattern. But healthy patterns may not be the best treatment following neurological injury. With a fully programmable robotic device there are innumerable variations to the training experience available. The use of rodent models enables us to test novel robotic gait training patterns and investigate their ability to improve overground locomotion as well as their ability to change the neuronal structure of the spinal cord following injury. We are currently investigating the effects of training in applied force fields instead of guided stepping patterns. Specifically, we are robotically training rats in viscous fields as well as negative viscosity fields after an incomplete cervical spinal cord injury and measuring the changes in the overground locomotion. Additionally, we are using manganese enhanced MRI techniques and diffusion tensor imaging tractography to investigate how our novel gait training induces changes in the activity of the spinal interneurons around the injury site. We hope that these studies will uncover better training techniques that can be quickly applied to the clinical setting to improve the locomotion of patients following neurological injury.
Regulated secretion is a critical process by which cells deliver molecules to the cell surface and extracellular space. Secreted cargo is synthesized in the endoplasmic reticulum, traverses the Golgi apparatus and is subsequently loaded into secretory vesicles. Secretion occurs in response to an external stimulus and involves directed vesicle movement, docking with the plasma membrane, fusion pore formation, and vesicle collapse to release cargo. Aberrant secretion is the cause of many human diseases. Defining the factors involved in secretion is crucial to develop therapeutic targets for these diseases.
Drosophila salivary glands are the largest secretory structures of the fly and represent a tractable experimental system for studying the factors that regulate hormone-induced secretion. To this end, I perform real time imaging on living salivary glands to elucidate the mechanisms and kinetics of secretion. By using confocal and spinning disc microscopy in combination with fluorescently tagged proteins, I can directly visualize the steps involved in cargo secretion and the role of the actin cytoskeleton during regulated secretion. By combining these approaches with Drosophila genetics I am defining the discrete events of regulated secretion and novel genes involved in this biologically relevant process.
Researchers in the field of positive psychology have discovered a number of benefits associated with positive emotions. Dr. Cabrera will discuss how these benefits contribute to success and well-being and will highlight specific strategies that can be used to create a more positive workplace where employees can thrive. She will also present a second dimension, in addition to positive emotions, that scientists believe is essential for our well-being.
Dr. Ayres will discuss his recent book The Bubble Economy (MIT Press, 2014; ISBN: 9780262027434). An abstract for his talk will follow, but the publisher offers the following information about about the book:
The global economy has become increasingly, perhaps chronically, unstable. Since 2008, we have heard about the housing bubble, subprime mortgages, banks “too big to fail,” financial regulation (or the lack of it), and the European debt crisis. Wall Street has discovered that it is more profitable to make money from other people’s money than by investing in the real economy, which has limited access to capital–resulting in slow growth and rising inequality. What we haven’t heard much about is the role of natural resources–energy in particular–as drivers of economic growth, or the connection of “global warming” to the economic crisis. In The Bubble Economy, Robert Ayres–an economist and physicist–connects economic instability to the economics of energy.
Ayres describes, among other things, the roots of our bubble economy (including the divergent influences of Senator Carter Glass–of the Glass-Steagall Law–and Ayn Rand); the role of energy in the economy, from the “oil shocks” of 1971 and 1981 through the Iraq wars; the early history of bubbles and busts; the end of Glass-Steagall; climate change; and the failures of austerity.
Finally, Ayres offers a new approach to trigger economic growth. The rising price of fossil fuels (notwithstanding “fracking”) suggests that renewable energy will become increasingly profitable. Ayres argues that government should redirect private savings and global finance away from home ownership and toward “de-carbonization”–investment in renewables and efficiency. Large-scale investment in sustainability will achieve a trifecta: lowering greenhouse gas emissions, stimulating innovation-based economic growth and employment, and offering long-term investment opportunities that do not depend on risky gambling strategies with derivatives.
Electron microscopes (EM) can now provide the nanometer resolution that is needed to image synapses, and therefore connections, while Light Microscopes (LM) see at the micrometer resolution required to model the 3D structure of the dendritic network. Since both the arborescence and the connections are integral parts of the brain’s wiring diagram, combining these two modalities is critically important.
In this talk, I will therefore present our approach to building the dendritic arborescence, to segmenting intra-neuronal structures from EM images, and to registering the resulting models. I will also argue that the techniques that are in wide usage in the Computer Vision and Machine Learning community are just as applicable in this context.]]>
The brain is a densely and precisely wired circuit made of heterogeneous cells, which themselves are complex computational devices made of an incredible repertoire of molecules. Our group develops tools for mapping, recording from, controlling, and building brain circuits, in order to reveal how they work, as well as to open up new therapeutic avenues. We have developed genetically-encoded reagents that, when expressed in specific neurons, enable their electrical activities to be precisely driven or silenced in response to millisecond timescale pulses of light. I will give an overview of these optogenetic tools, adapted from natural photosensory and photosynthetic proteins, and discuss new tools we are developing, including molecules that enable multiplexed, noninvasive, and ultraprecise optical neural control, even of endogenous signaling pathways. We are developing, often working in interdisciplinary collaborations, microfabricated hardware to enable complex and distributed neural circuits to be controlled and recorded in a fully 3-D fashion, new kinds of microscopes capable of whole-nervous system neural activity imaging, robots that can automatically record neurons intracellularly and integratively in live brain, and strategies for building 3-D brain circuits in vitro. We aim to provide these tools to the neuroscience community in order to open up new fundamental as well as clinically relevant explorations of how to observe and repair brain circuits, and to apply these tools systematically to the mapping and engineering of entire brains.
The Panic of 1893 was the worst economic crisis encountered by the century-old United States. Like the Great Depression, the 1890’s presented a double dip recession with associated bank panics. Unlike the Depression, in 1893 there was little regulatory infrastructure in place to deal with the ensuing economic problems. Unique about 1893 is the existence, in Helena, Montana, of very detailed banking records that provide insights into actions taken by individuals during the Panic. This presentation will focus on findings resulting from my investigations of these records, illustrating the characteristics of the Panic. Econometric analysis demonstrates the spread of panic, and an agent based model recreates some of the features of the panic by using agents whose behavior is driven completely by emotional contagion.]]>