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!
Medical gamma-ray camera is now palm-sized
23.05.2017 | Waseda University
Computer accurately identifies and delineates breast cancers on digital tissue slides
11.05.2017 | Case Western Reserve University
Staphylococcus aureus is a feared pathogen (MRSA, multi-resistant S. aureus) due to frequent resistances against many antibiotics, especially in hospital infections. Researchers at the Paul-Ehrlich-Institut have identified immunological processes that prevent a successful immune response directed against the pathogenic agent. The delivery of bacterial proteins with RNA adjuvant or messenger RNA (mRNA) into immune cells allows the re-direction of the immune response towards an active defense against S. aureus. This could be of significant importance for the development of an effective vaccine. PLOS Pathogens has published these research results online on 25 May 2017.
Staphylococcus aureus (S. aureus) is a bacterium that colonizes by far more than half of the skin and the mucosa of adults, usually without causing infections....
Physicists from the University of Würzburg are capable of generating identical looking single light particles at the push of a button. Two new studies now demonstrate the potential this method holds.
The quantum computer has fuelled the imagination of scientists for decades: It is based on fundamentally different phenomena than a conventional computer....
An international team of physicists has monitored the scattering behaviour of electrons in a non-conducting material in real-time. Their insights could be beneficial for radiotherapy.
We can refer to electrons in non-conducting materials as ‘sluggish’. Typically, they remain fixed in a location, deep inside an atomic composite. It is hence...
Two-dimensional magnetic structures are regarded as a promising material for new types of data storage, since the magnetic properties of individual molecular building blocks can be investigated and modified. For the first time, researchers have now produced a wafer-thin ferrimagnet, in which molecules with different magnetic centers arrange themselves on a gold surface to form a checkerboard pattern. Scientists at the Swiss Nanoscience Institute at the University of Basel and the Paul Scherrer Institute published their findings in the journal Nature Communications.
Ferrimagnets are composed of two centers which are magnetized at different strengths and point in opposing directions. Two-dimensional, quasi-flat ferrimagnets...
An Australian-Chinese research team has created the world's thinnest hologram, paving the way towards the integration of 3D holography into everyday...
24.05.2017 | Event News
23.05.2017 | Event News
22.05.2017 | Event News
26.05.2017 | Life Sciences
26.05.2017 | Life Sciences
26.05.2017 | Physics and Astronomy