Thank you Nathalia and Juan

Great posts from my colleagues Nathalia and Juan….I’m sure their research will be a fine addition to the Krasnow research portfolio.

Here in Woods Hole, today is the first day of the General Scientific Meetings–a two day affair devoted to summer research findings that has a very very long history. This evening, the Woods Hole neuroscience community will get together for the annual wine and cheese reception at the Swope Center-as it also does annually at the Society for Neuroscience meeting.

In the meantime, today we have the first taste of Fall….Vineyard sound and the sky are crystal clear blue and the humidity of summer has been replaced with the crispness that precedes the change in season.

Jim

Background & research interests

I have also been invited by Jim to introduce myself. Since I’m about to start, in a couple of weeks, as assistant professor of the Dept. of Electrical and Computer Engineering at GMU, I thought it would be useful to briefly describe my background, and then discuss my research interests.

My research started with the retinal spreading depression, which is an experimental model for migraine auras. I developed models and demonstrated that this phenomenon can be explained with either cellular automata and/or reaction-diffusion equations that emulate wave propagation in anisotropic media and spiral formation. The results of these experiments constituted my Master’s thesis. Afterwards I developed a test system for the German retina implant project, based on in vitro chicken eyecups, and also tested in vivo stimulation parameters in anesthetized rabbits. I then received a fellowship to design “neuroelectronic arrays”, consisting of two- and three-dimensional microelectrode arrays for recording electrical activity of neurons in culture. After receiving my Ph.D., I went to Stanford University as a postdoc. There I investigated cardiac cell responses to changes in metabolism. Cell cultures were grown on microfabricated Clark-type oxygen sensors, and submitted to various drugs which modulated sensor responses. For the last two years I have been involved in developing seizure control devices and electrode design for low frequency stimulation.

Now that I am about to start my own lab, I intend to continue some of the efforts described above, in particular developing sensors coated with intelligent materials. Intelligent materials are polymers or polymeric coatings which react to environment or substrate stimuli (such as light, voltage, and pH). Potential applications of these sensors are multifold: from tissue engineering and implantable devices to traditional MEMS applications (actuators, development of electronic nose for detection of oil or alcohol in unsafe environments). I’m also interested in the spreading depression phenomenon in slices, in particular under the effect of electric fields. I hypothesize that some symptoms from migraines evolve due to charge imbalance in the nervous system and that they can be modulated experimentally and modeled in a very straightforward way.

Welcoming the new academic year

One of our staff drew my attention to some new digital photos of our
new Krasnow laboratory expansion yesterday. It’s amazing how much
it’s changed in the ten days or so since I left for Woods Hole. It
reminds me of how rapidly the new academic year is approaching. For
me the new academic year is always symbolic of turning a clean page–
in a way that is much more salient than the calendar new year. At
Krasnow this is a very special new academic year because it coincides
with the welcoming of four new PI’s to our scientific community: Rob
Axtell (with the Center for Social Complexity), Juan Cebral (who
wrote about his work very recently in this blog), Nathalia Peixoto
(with the Center for Neural Dynamics) and Jim Thompson (who will be
joining NICKI). We are also actively participating in two new
searches and my hope is that we’ll be welcoming two additional PI’s
next Fall as we begin to fill out the Institute’s new space.

At the same time, we’ll be adding a new Center (more about that soon)
to be led by Giorgio Ascoli and we’ll commence regular dedicated
research operations of the new brain imaging center (NICKI) under the
able leadership of Layne Kalbfleisch and Kevin McCabe. We’ll have a
significant celebratory event sometime in the Fall to publicly
acknowledge these major new initiatives.

This has been a summer of major space moves: the Center for Social
Complexity has moved into its extraordinary new dedicated space
(which includes an enormous “simulation wall”). In addition, the
laboratory of Kimberly “Avrama” Blackwell has now moved into new
space more suitable for neurophysiology. So with NICKI, the Institute
is now very much reconfigured–I hope that old friends will consider
visiting, just to get a feel for the new layout and meet the new folks.

None of this would be possible without the continued efforts of the
incredibly dedicated Krasnow staff: Joe Carls, Marcy Moe, Cindy
Roberts, Jennifer Sturgis and Jane Wendelin. They have worked
tirelessly through the Summer to get things ready for the new
semester. We’re also very lucky to have, as Associate Director (and
CIO), Ken DeJong (who also happens to lead the Krasnow Adaptive
Systems Laboratory). Ken has played a key role in backing me up this
summer as I traveled extensively and supervising the massive changes
in our computer subnet that have been made necessary by the new MRI
and other security issues.

Finally a word about a very special event that will be coming in the
Spring: the Institute will be holding a major symposium to celebrate
its “coming of age” and to mark a new initiative to study the human
mind: among the confirmed speakers are Floyd Bloom, John Holland,
Nancy Kanwisher, Patricia Churchland, Vernon Smith and Guilio Tononi. I’ll have
much more on this scientific event later in the academic year. But
thanks clearly need to go to Krasnow Director Emeritus, Harold
Morowitz and his assistant Sara Bradley for all of their work getting
this important project going.

Finally, this will be an academic year of transition for me: I’ll be
planning for my second appointed term as Krasnow Director–due to
commence next July. I will be consulting extensively with all of our
faculty and staff about those plans and hope to go public with them
here on this blog sometime next May.

Jim

Research Update – Juan R. Cebral

I am an Associate Professor in the Computational and Data Sciences Department of the College of Sciences at GMU and the Center for Computational Fluid Dynamics. Recently, I have been invited by Jim to join Krasnow and to write a summary of our research. Here it is…

Stroke is the third cause of death after heart disease and cancer, and the leading cause of long term disability. Strokes can be ischemic (due to a diminution of blood supply to the brain) or hemorrhagic (bleeding into the brain). Ischemic strokes are most commonly caused by the blockage of a feeding vessel due to athersclerotic narrowing of the vessels or due to emboli. The major source of ischemic stroke is carotid artery atherosclerosis. Hemorrhagic strokes are most commonly due to the rupture of a cerebral aneurysm. Cerebral aneurysms are pathological dilatations of the arterial wall, typically located at or near arterial bifurcations in the circle of Willis. The vascular architecture of the brain is unique in the human body because the circle of Willis provides a redundant network of vessels, reflecting the important nature of a constant oxygen supply to the brain.

Our current research focuses on intracranial aneurysms. With advances in modern medical imaging techniques, unruptured aneurysms are more frequently detected. Because the prognosis of cerebral hemorrhage is still very poor, preventive treatment is frequently performed. However, the risks associated with surgical and endovascular interventions may exceed the rupture risk of the aneurysm if left untreated. Therefore, the best option would be to treat only those patients at higher risk. This requires a better understanding of the mechanisms responsible for aneurysm initiation, growth and rupture. Previous studies have identified the major factors involved in these processes: a) arterial hemodynamics (blood flows), b) arterial mechanobiology, and c) the peri-aneurysmal environment.

Our research goals are to better understand the mechanisms of aneurysm development, progression and rupture, to develop computational tools for assessing the rupture risk of individual patients, and to optimize and peronalize minimally invasive endovascular procedures to treat these patients. To this end, we are constructing patient-specific computational fluid dynamics models of brain aneurysms from 3D rotational angiography images in order to quantify the in vivo blood flow patterns and hemodynamic forces on the aneurysm walls. Using this methodology, we are developing a database of cerebral aneurysms that contains, clinical information, medical images and computational models of blood flow patterns. We are using all this information to study possible relationships between anatomical and hemodynamic characteristics and clinical events such as aneurysm rupture or the development of symptoms. In parallel, we are developing techniques to simulate blood flows after deployment of endovascular devices such as coils and stents used to treat these aneurysms. This is a challenging problem because of the complex geometry of the vessel and the devices. However, we are using a so called mesh embedding approach that greatly simplifies this problem and allows us to perform “virtual” interventions in order to predict what the effects of a given device would be for a particular patient. This would allow us to select the best treatment option for an individual. This is quite important for aneurysms that are difficult to treat with coils or by surgical clipping. In addition, we are constructing models of the circle of Willis from magnetic resonance angiography images of normal subjects in order to characterize the vascular architecture of the brain and the hemodynamic patterns in the main arteries feeding the brain. This information is important for prescribing “typical” physiologic flow conditions in the simulations when they are not available for an given patient. It is also important for understanding the role of hemodynamics in the process of aneurysm initiation, and the role of the collateral pathways provided by the circle of Willis during arterial occlusions and medical interventions.

Our research is highly multidisciplinary, it involves medical image analysis, computational geometry, computational fluid dynamics, high performance computing, computer graphics and visualization, biomechanics, cell mechanotransduction, and clinical research. For this reason we are collaborating with a number of colleagues in the US and around the world. In particular, we maintain a strong collaboration with the Neuroradiology division of Inova Fairfax Hospital, the Interventional Neuroradiology unit at UCLA (the largest site for cerebral aneurysms) and with the Computational Imaging Lab of the Pompeu Fabra University in Barcelona, Spain.

Support for this research has come from the Whitaker Foundation, Philips Medical Systems and the American Heart Association.

We look forward to continuing our research in this exciting area and to make an impact on the way medicine is practiced today. Transforming medicine into a predictive science has the potential of tremendously improving patient evaluation and management, which is our ultimately objective.

JRC

Woods Hole: the heat is on

Yes….it’s even hot in Woods Hole, although the high 80’s can’t compare to what the rest of the East Coast of the US is experiencing. And by evening, with the sea breezes, it’s pretty comfortable. Nevertheless, the first annual Ed Kravitz MBL lecture last night (Eve Marder, the new President of the Society for Neuroscience) was moved from the non-airconditioned Meigs Room to Whitman Auditorium where cool is the rule.

Marder’s talk last night was devoted to a model neuronal network of approximately 30 cells that she has worked on all her career: the crustacean stomatogastic ganglion (STG). Several interesting neural dynamics themes in her talk:

First, understanding the rules that allows for compensation in the neuronal and network function between and within-individuals.

Second, how tightly tuned are the intrinsic parameters for “good enough” appropriate network behaviors.

For me, the most interesting result is how mRNA copy number of ionic channels is very closely correlated to the magnitude of the corresponding ionic currents…and how the ratio of correlated mRNA expression of two channel types varies by STG cell type.

Marder is a professor at Brandeis–she publishes often in Nature Neuroscience.

Today I am having lunch with Gary Borisy, the newly installed Director and CEO of the MBL. It’ll be interesting to compare notes with him.

Jim

Blogging pause

It’s been a busy week getting ready for Woods Hole. The new MRI is however producing functional BOLD images, as advertised, so thanks to the Siemens engineers and our own folks including new MR tech Marcy Moe for their efforts. Next week’s Woods Hole activities include a workshop on hippocampus and a talk by Jeff Lichtman on Connectomics. We’ll also have the annual MBL Corporation meeting, which I’m very much looking forward to.

But before we can get to those enjoyable activities, there’s first the small matter of driving up the I95 corridor with two dogs, my wife Robin, and hopefully enough sandwiches and snacks to avoid the hated New Jersey Turnpike rest areas.

Jim

Returning to Woods Hole

Next week, I’ll have returned to Woods Hole to begin two weeks of summer residency at the Marine Biological Laboratory (MBL). As with last year, I’ll be there in my role as editor of The Biological Bulletin, although I hope to also continue to build the relationship between the MBL and the Krasnow Institute for Advanced Study.

MBL of course has a new director and CEO, in Gary Borisy, the discover of tubulin. I am very much looking forward to meeting him.

And of course MBL is surrounded on three sides by the Atlantic Ocean, so I’m looking forward to putting up some spectacular images of what for me is the most beautiful place to do science in the world.

Jim

Thanks for the party!

Thank you to all who put together a wonderful suprise 50th birthday party for me today. I’m particularly grateful to Ginger and Len Pomata for making it out to Krasnow for the party and to see our new Brain Imaging Center.

Jim