The Weizmann Institute of Science is a public research university in Rehovot, Israel. It differs from other Israeli universities in that it offers only graduate and postgraduate tutelage in the science.It is a multidisciplinary research center, with around 2,500 scientists, postdoctoral fellows, Ph.D. and M.Sc. students, and scientific, technical, and administrative staff working at the Institute.Three Nobel laureates and three Turing Award laureates have been associated with the Weizmann Institute of Science. Wikipedia.
Weizmann Institute of Science | Date: 2016-08-22
A system and methods for controlling pulse parameters during transcranial magnetic stimulation are provided. Multiple coils are placed on external body parts, and are controlled using an external control unit coupled to a stimulator having fast switches. The timing of the switches, as well as other parameters within the stimulator, determine the pulse parameters, such as pulse shape. The variety of pulse shapes obtainable using such a system and methods provides controlled physiologic effects within an internal body organ.
Likhtik E.,1051 Riverside Drive |
Paz R.,Weizmann Institute of Science
Trends in Neurosciences | Year: 2015
The study of neurobiological mechanisms underlying anxiety disorders has been shaped by learning models that frame anxiety as maladaptive learning. Pavlovian conditioning and extinction are particularly influential in defining learning stages that can account for symptoms of anxiety disorders. Recently, dynamic and task related communication between the basolateral complex of the amygdala (BLA) and the medial prefrontal cortex (mPFC) has emerged as a crucial aspect of successful evaluation of threat and safety. Ongoing patterns of neural signaling within the mPFC-BLA circuit during encoding, expression and extinction of adaptive learning are reviewed. The mechanisms whereby deficient mPFC-BLA interactions can lead to generalized fear and anxiety are discussed in learned and innate anxiety. Findings with cross-species validity are emphasized. © 2014 Elsevier Ltd.
Finkelstein A.,Weizmann Institute of Science
Nature | Year: 2014
Navigation requires a sense of direction (‘compass’), which in mammals is thought to be provided by head-direction cells, neurons that discharge when the animal’s head points to a specific azimuth. However, it remains unclear whether a three-dimensional (3D) compass exists in the brain. Here we conducted neural recordings in bats, mammals well-adapted to 3D spatial behaviours, and found head-direction cells tuned to azimuth, pitch or roll, or to conjunctive combinations of 3D angles, in both crawling and flying bats. Head-direction cells were organized along a functional–anatomical gradient in the presubiculum, transitioning from 2D to 3D representations. In inverted bats, the azimuth-tuning of neurons shifted by 180°, suggesting that 3D head direction is represented in azimuth × pitch toroidal coordinates. Consistent with our toroidal model, pitch-cell tuning was unimodal, circular, and continuous within the available 360° of pitch. Taken together, these results demonstrate a 3D head-direction mechanism in mammals, which could support navigation in 3D space. © 2014 Nature Publishing Group, a division of Macmillan Publishers Limited. All Rights Reserved.
Rishal I.,Weizmann Institute of Science |
Fainzilber M.,Weizmann Institute of Science
Nature Reviews Neuroscience | Year: 2014
The extensive lengths of neuronal processes necessitate efficient mechanisms for communication with the cell body. Neuronal regeneration after nerve injury requires new transcription; thus, long-distance retrograde signalling from axonal lesion sites to the soma and nucleus is required. In recent years, considerable progress has been made in elucidating the mechanistic basis of this system. This has included the discovery of a priming role for early calcium waves; confirmation of central roles for mitogen-activated protein kinase signalling effectors, the importin family of nucleocytoplasmic transport factors and molecular motors such as dynein; and demonstration of the importance of local translation as a key regulatory mechanism. These recent findings provide a coherent mechanistic framework for axon-soma communication in the injured nerve and shed light on the integration of cytoplasmic and nuclear transport in all eukaryotic cells. © 2014 Macmillan Publishers Limited. All rights reserved.
Dudai Y.,Weizmann Institute of Science
Annual Review of Neuroscience | Year: 2012
Memory consolidation is the hypothetical process in which an item in memory is transformed into a long-term form. It is commonly addressed at two complementary levels of description and analysis: the cellular/synaptic level (synaptic consolidation) and the brain systems level (systems consolidation). This article focuses on selected recent advances in consolidation research, including the reconsolidation of long-term memory items, the brain mechanisms of transformation of the content and of cue-dependency of memory items over time, as well as the role of rest and sleep in consolidating and shaping memories. Taken together, the picture that emerges is of dynamic engrams that are formed, modified, and remodified over time at the systems level by using synaptic consolidation mechanisms as subroutines. This implies that, contrary to interpretations that have dominated neuroscience for a while, but similar to long-standing cognitive concepts, consolidation of at least some items in long-term memory may never really come to an end. © 2012 by Annual Reviews. All rights reserved.
Gunanathan C.,National Institute of Science Education and Research NISER |
Milstein D.,Weizmann Institute of Science
Chemical Reviews | Year: 2014
Activation of inert chemical bonds by transition metal complexes is an area of utmost importance. Efficient bond activation can provide a leading entry to successful catalytic design with the potential of providing greener synthetic methods for useful products. These coordinatively saturated and unsaturated ruthenium pincer complexes with heteroaromatic and aliphatic backbones developed in recent years exhibit new reactivities, activate strong chemical bonds, and act as efficient catalysts for several synthetic methods including unprecedented green transformations, the pivotal interest of this Review. One of the characteristic properties of pincer complexes is the ability to stabilize low valent metal complexes with uncommon geometries.
Klajn R.,Weizmann Institute of Science
Chemical Society Reviews | Year: 2014
In the past few years, spiropyran has emerged as the molecule-of-choice for the construction of novel dynamic materials. This unique molecular switch undergoes structural isomerisation in response to a variety of orthogonal stimuli, e.g. light, temperature, metal ions, redox potential, and mechanical stress. Incorporation of this switch onto macromolecular supports or inorganic scaffolds allows for the creation of robust dynamic materials. This review discusses the synthesis, switching conditions, and use of dynamic materials in which spiropyran has been attached to the surfaces of polymers, biomacromolecules, inorganic nanoparticles, as well as solid surfaces. The resulting materials show fascinating properties whereby the state of the switch intimately affects a multitude of useful properties of the support. The utility of the spiropyran switch will undoubtedly endow these materials with far-reaching applications in the near future. © 2014 The Royal Society of Chemistry.
Lev S.,Weizmann Institute of Science
Nature Reviews Molecular Cell Biology | Year: 2010
The movement of lipids within and between intracellular membranes is mediated by different lipid transport mechanisms and is crucial for maintaining the identities of different cellular organelles. Non-vesicular lipid transport has a crucial role in intracellular lipid trafficking and distribution, but its underlying mechanisms remain unclear. Lipid-transfer proteins (LTPs), which regulate diverse lipid-mediated cellular processes and accelerate vectorial transport of lipid monomers between membranes in vitro, could potentially mediate non-vesicular intracellular lipid trafficking. Understanding the mechanisms by which lipids are transported and distributed between cellular membranes, and elucidating the role of LTPs in intracellular lipid transport and homeostasis, are currently subjects of intensive study. © 2010 Macmillan Publishers Limited. All rights reserved.
Fass D.,Weizmann Institute of Science
Annual Review of Biophysics | Year: 2012
It has been known for many decades that cell surface, soluble-secreted, and extracellular matrix proteins are generally rich in disulfide bonds, but only more recently has the functional diversity of disulfide bonding in extracellular proteins been appreciated. In addition to the classic mechanisms by which disulfide bonds enhance protein thermodynamic stability, disulfides in certain configurations contribute particular mechanical properties to proteins that sense and respond to tensile forces. Disulfides may help warp protein folds for the evolution of new functions, or they may fasten aggregation-prone flaps of polypeptide to protein surfaces to prevent fibrilization or oligomerization. Disulfides can also be used to package and secure macromolecular cargo for intercellular transport. A series of case studies illustrating diverse biophysical roles of disulfide bonding are reviewed, with a focus on proteins functioning in the extracellular environment. © 2012 by Annual Reviews. All rights reserved.
Geiger B.,Weizmann Institute of Science
Cold Spring Harbor perspectives in biology | Year: 2011
Cell adhesions mediate important bidirectional interactions between cells and the extracellular matrix. They provide an interactive interface between the extracellular chemical and physical environment and the cellular scaffolding and signaling machinery. This dynamic, reciprocal regulation of intracellular processes and the matrix is mediated by membrane receptors such as the integrins, as well as many other components that comprise the adhesome. Adhesome constituents assemble themselves into different types of cell adhesion structures that vary in molecular complexity and change over time. These cell adhesions play crucial roles in cell migration, proliferation, and determination of cell fate.