By automating and standardizing the process in which brain samples are divided into sections and then imaged sequentially at precise spatial orientations in two-photon microscopes, the team, led by Assoc. Prof. Pavel Osten and consisting of scientists from his CSHL lab and the Massachusetts Institute of Technology, has opened the door to making whole-brain mapping routine.
Specifically, says Osten, "the new technology should greatly facilitate the systematic study of neuroanatomy in mouse models of human brain disorders such as schizophrenia and autism."
The new technology, developed in concert with TissueVision of Cambridge, Mass. and reported on in a paper appearing online Jan. 15 in Nature Methods, is called Serial Two-Photon Tomography, or STP tomography. Tomography refers to any process (including the familiar CAT and PET scans used in medical diagnostics) that images an object section by section, by shooting penetrating waves through it. Computers powered by mathematical formulae reassemble the results to produce a three-dimensional rendering. Two-photon imaging is a type used in biology laboratories, particularly in conjunction with fluorescent biomarkers, which can be mobilized to illuminate specific cell types or other anatomical features. The two-photon method allows deeper optical penetration into the tissue being sampled than conventional confocal microscopy.
As Osten explains, STP tomography achieves high-throughput fluorescence imaging of whole mouse brains via robotic integration of the two fundamental steps -- tissue sectioning and fluorescence imaging. In their paper, his team reports on the results of several mouse-brain imaging experiments, which indicate the uses and sensitivity of the new tool. They conclude that it is sufficiently mature to be used in whole-brain mapping efforts such as the ongoing Allen Mouse Brain Atlas project.
One set of experiments tested the technology at different levels of resolution. At 10x magnification of brain tissue samples, they performed fast imaging "at a resolution sufficient to visualize the distribution and morphology of green-fluorescent protein-labeled neurons, including their dendrites and axons," Osten reports.
A full set of data, including final images, could be obtained by the team in 6.5 to 8.5 hours per brain, depending on the resolution. These sets each were comprised of 260 top-to-bottom, or coronal, slices of mouse brain tissue, which were assembled by computer into three-dimensional renderings themselves capable of a wide range of "warping," i.e., artificial manipulation, to reveal hidden structures and features.
"The technology is a practical one that can be used for scanning at various levels of resolution, ranging from 1 to 2 microns to less than a micron," Osten says. Scans at the highest resolution level take about 24 hours to collect. This makes possible an impressive saving of time, Osten says, compared to methods that are now in use. Using these, it would take an experienced technician about a week to collect a set of whole-brain images at high resolution, he noted.
"What is most exciting about this tool is its application in the study of mouse models of human illness, which we are already doing in my lab," Osten says. "We are focusing on making comparisons between different mouse models of schizophrenia and autism. Many susceptibility genes have been identified in both disorders – one recent estimate by Dr. Mike Wigler's team here at CSHL put the figure at over 250 for autism spectrum disorders, for instance. Dr. Alea Mills at CSHL has published a mouse model of one genetic aberration in autism – a region on chromosome 16 – and soon we will have tens of models, each showing a different aberration.
"We will want to compare these mice, and that is essentially why we designed STP tomography – to automate and standardize the process of collecting whole-brain images in which different cell-types or circuit tracings have been performed. This makes possible comparisons across different mouse models in an unbiased fashion."
"Serial two-photon tomography: an automated method for mouse brain imaging" appears online in Nature Methods on January 15, 2012. The authors are: Timothy Ragan, Lolahon R Kadiri, Kannan Umadevi Venkataraju, Karsten Bahlmann, Jason Sutin, Julian Taranda, Ignacio Arganda-Carreras, Yongsoo Kim, H Sebastian Seung and Pavel Osten. the paper can be obtained online at http://www.nature.com/nmeth/index.html
This research was supported by grants from: The Simons Foundation, The McKnight Foundation, the Howard Hughes Medical Institute, and the National Institutes of Health.
About Cold Spring Harbor Laboratory
Founded in 1890, Cold Spring Harbor Laboratory (CSHL) has shaped contemporary biomedical research and education with programs in cancer, neuroscience, plant biology and quantitative biology. CSHL is ranked number one in the world by Thomson Reuters for impact of its research in molecular biology and genetics. The Laboratory has been home to eight Nobel Prize winners. Today, CSHL's multidisciplinary scientific community is more than 350 scientists strong and its Meetings & Courses program hosts more than 11,000 scientists from around the world each year. Tens of thousands more benefit from the research, reviews, and ideas published in journals and books distributed internationally by CSHL Press. The Laboratory's education arm also includes a graduate school and programs for undergraduates as well as middle and high school students and teachers. CSHL is a private, not-for-profit institution on the north shore of Long Island. For more information, visit www.cshl.edu.
Peter Tarr | EurekAlert!
Stretchable, wearable coils may make MRI, other medical tests easier on patients
26.02.2020 | Purdue University
Therapies without drugs
25.02.2020 | Fraunhofer-Institut für Zuverlässigkeit und Mikrointegration IZM
Researchers at the University of Bayreuth have discovered an unusual material: When cooled down to two degrees Celsius, its crystal structure and electronic properties change abruptly and significantly. In this new state, the distances between iron atoms can be tailored with the help of light beams. This opens up intriguing possibilities for application in the field of information technology. The scientists have presented their discovery in the journal "Angewandte Chemie - International Edition". The new findings are the result of close cooperation with partnering facilities in Augsburg, Dresden, Hamburg, and Moscow.
The material is an unusual form of iron oxide with the formula Fe₅O₆. The researchers produced it at a pressure of 15 gigapascals in a high-pressure laboratory...
Study by Mainz physicists indicates that the next generation of neutrino experiments may well find the answer to one of the most pressing issues in neutrino physics
Among the most exciting challenges in modern physics is the identification of the neutrino mass ordering. Physicists from the Cluster of Excellence PRISMA+ at...
Fraunhofer researchers are investigating the potential of microimplants to stimulate nerve cells and treat chronic conditions like asthma, diabetes, or Parkinson’s disease. Find out what makes this form of treatment so appealing and which challenges the researchers still have to master.
A study by the Robert Koch Institute has found that one in four women will suffer from weak bladders at some point in their lives. Treatments of this condition...
The operational speed of semiconductors in various electronic and optoelectronic devices is limited to several gigahertz (a billion oscillations per second). This constrains the upper limit of the operational speed of computing. Now researchers from the Max Planck Institute for the Structure and Dynamics of Matter in Hamburg, Germany, and the Indian Institute of Technology in Bombay have explained how these processes can be sped up through the use of light waves and defected solid materials.
Light waves perform several hundred trillion oscillations per second. Hence, it is natural to envision employing light oscillations to drive the electronic...
Most natural and artificial surfaces are rough: metals and even glasses that appear smooth to the naked eye can look like jagged mountain ranges under the microscope. There is currently no uniform theory about the origin of this roughness despite it being observed on all scales, from the atomic to the tectonic. Scientists suspect that the rough surface is formed by irreversible plastic deformation that occurs in many processes of mechanical machining of components such as milling.
Prof. Dr. Lars Pastewka from the Simulation group at the Department of Microsystems Engineering at the University of Freiburg and his team have simulated such...
12.02.2020 | Event News
16.01.2020 | Event News
15.01.2020 | Event News
26.02.2020 | Physics and Astronomy
26.02.2020 | Interdisciplinary Research
26.02.2020 | Power and Electrical Engineering