La Jolla Salk Institute
La Jolla Salk Institute
Sato T.,University College London |
Nauhaus I.,La Jolla Salk Institute |
Carandini M.,University College London
Neuron | Year: 2012
Electrode recordings and imaging studies have revealed that localized visual stimuli elicit waves of activity that travel across primary visual cortex. Traveling waves are present also during spontaneous activity, but they can be greatly reduced by widespread and intensive visual stimulation. In this Review, we summarize the evidence in favor of these traveling waves. We suggest that their substrate may lie in long-range horizontal connections and that their functional role may involve the integration of information over large regions of space.
Briggs F.,Physiology and Neurobiology |
Kiley C.W.,University of California at Davis |
Callaway E.M.,La Jolla Salk Institute |
Usrey W.M.,University of California at Davis
Neuron | Year: 2016
Corticothalamic circuits are essential for reciprocal information exchange between the thalamus and cerebral cortex. Nevertheless, the role of corticothalamic circuits in sensory processing remains a mystery. In the visual system, afferents from retina to the lateral geniculate nucleus (LGN) and from LGN to primary visual cortex (V1) are organized into functionally distinct parallel processing streams. Physiological evidence suggests corticogeniculate feedback may be organized into parallel streams; however, little is known about the diversity of corticogeniculate neurons, their local computations, or the structure-function relationship among corticogeniculate neurons. We used a virus-mediated approach to label and reconstruct the complete dendritic and local axonal arbors of identified corticogeniculate neurons in the macaque monkey. Our results reveal morphological substrates for parallel streams of corticogeniculate feedback based on distinct classes of neurons in V1 and V2. These results support the hypothesis that distinct populations of feedback neurons provide independent and unique information to the LGN. © 2016 Elsevier Inc.
Striedter G.F.,University of California at Irvine |
Srinivasan S.,La Jolla Salk Institute |
Srinivasan S.,University of California at San Diego |
Monuki E.S.,University of California at Irvine
Annual Review of Neuroscience | Year: 2015
Why the cerebral cortex folds in some mammals but not in others has long fascinated and mystified neurobiologists. Over the past century-especially the past decade-researchers have used theory and experiment to support different folding mechanisms such as tissue buckling from mechanical stress, axon tethering, localized proliferation, and external constraints. In this review, we synthesize these mechanisms into a unifying framework and introduce a hitherto unappreciated mechanism, the radial intercalation of new neurons at the top of the cortical plate, as a likely proximate force for tangential expansion that then leads to cortical folding. The interplay between radial intercalation and various biasing factors, such as local variations in proliferation rate and connectivity, can explain the formation of both random and stereotypically positioned folds. © 2015 by Annual Reviews. All rights reserved.
Lopez-Otin C.,University of Oviedo |
Hunter T.,La Jolla Salk Institute
Nature Reviews Cancer | Year: 2010
Kinases and proteases are responsible for two fundamental regulatory mechanisms phosphorylation and proteolysis that orchestrate the rhythms of life and death in all organisms. Recent studies have highlighted the elaborate interplay between both post-translational regulatory systems. Many intracellular or pericellular proteases are regulated by phosphorylation, whereas multiple kinases are activated or inactivated by proteolytic cleavage. The functional consequences of this regulatory crosstalk are especially relevant in the different stages of cancer progression. What are the clinical implications derived from the fertile dialogue between kinases and proteases in cancer?
Lemke G.,La Jolla Salk Institute
Cold Spring Harbor Perspectives in Biology | Year: 2013
The TAM receptors-Tyro3, Axl, and Mer-comprise a unique family of receptor tyrosine kinases, in that as a group they play no essential role in embryonic development. Instead, they function as homeostatic regulators in adult tissues and organ systems that are subject to continuous challenge and renewal throughout life. Their regulatory roles are prominent in the mature immune, reproductive, hematopoietic, vascular, and nervous systems. The TAMs and their ligands-Gas6 and Protein S-are essential for the efficient phagocytosis of apoptotic cells and membranes in these tissues; and in the immune system, theyact as pleiotropic inhibitors of the innate inflammatory response to pathogens. Deficiencies in TAM signaling are thought to contribute to chronic inflammatory and autoimmune disease in humans, and aberrantly elevated TAMsignaling is strongly associated with cancer progression, metastasis, and resistance to targeted therapies. © 2013 Cold Spring Harbor Laboratory Press; all rights reserved.
Verma I.M.,La Jolla Salk Institute
Science | Year: 2013
Gene therapy trials show a beneficial effect in children suffering from a neurodegenerative disorder or an immunodeficiency disease.
Rothlin C.V.,Yale University |
Lemke G.,La Jolla Salk Institute
Current Opinion in Immunology | Year: 2010
The TAM receptor tyrosine kinases Tyro3, Axl, and Mer and their ligands Gas6 and Protein S are essential for the phagocytosis of apoptotic cells and membranes in the adult immune, nervous, and reproductive systems. Genetic studies indicate that this receptor-ligand system is central to apoptotic cell engulfment that is triggered by the 'eat-me' signal phosphatidylserine (PtdSer). At the same time, TAM signaling is normally activated by Toll-like receptor (TLR) and type I interferon signaling, as part of the innate inflammatory response in dendritic cells (DCs) and macrophages, where it inhibits this response. Deficiencies in TAM signaling result in human retinal dystrophies and may contribute to lupus and other human autoimmune diseases. © 2010 Elsevier Ltd.
Bellin M.,Leiden University |
Marchetto M.C.,La Jolla Salk Institute |
Gage F.H.,La Jolla Salk Institute |
Mummery C.L.,Leiden University
Nature Reviews Molecular Cell Biology | Year: 2012
Worldwide increases in life expectancy have been paralleled by a greater prevalence of chronic and age-associated disorders, particularly of the cardiovascular, neural and metabolic systems. This has not been met by commensurate development of new drugs and therapies, which is in part owing to the difficulty in modelling human diseases in laboratory assays or experimental animals. Patient-specific induced pluripotent stem (iPS) cells are an emerging paradigm that may address this. Reprogrammed somatic cells from patients are already applied in disease modelling, drug testing and drug discovery, thus enabling researchers to undertake studies for treating diseases 'in a dish', which was previously inconceivable. © 2012 Macmillan Publishers Limited. All rights reserved.
Stevens C.F.,La Jolla Salk Institute
Proceedings of the National Academy of Sciences of the United States of America | Year: 2015
The primary visual cortex is organized in a way that assigns a specific collection of neurons the job of providing the rest of the brain with all of the information it needs about each small part of the image present on the retina: Neighboring patches of the visual cortex provide the information about neighboring patches of the visual world. Each one of these cortical patches-often identified as a "pinwheel"-contains thousands of neurons, and its corresponding image patch is centered on a particular location in the retina. For stimuli within their image patch, neurons respond selectively to lines or edges with a particular slope (orientation tuning) and to regions of the patch of different sizes (known as spatial frequency tuning). The same number of neurons is devoted to reporting each possible slope (orientation). For the cells that cover different-sized regions of their image patch, however, the number of neurons assigned depends strongly on their preferred region size. Only a few neurons report on large and small parts of the image patch, but many neurons report visual information from medium-sized areas. I show here that having different numbers of neurons responsible for image regions of different sizes actually carries out a computation: Edges in the image patch are extracted. I also explain how this edge-detection computation is done.
Rivier C.,La Jolla Salk Institute
Frontiers in Neuroendocrinology | Year: 2014
Alcohol stimulates the hypothalamic-pituitary-adrenal (HPA) axis through brain-based mechanisms in which endogenous corticotropin-releasing factor (CRF) plays a major role. This review first discusses the evidence for this role, as well as the possible importance of intermediates such as vasopressin, nitric oxide and catecholamines. We then illustrate the long-term influence exerted by alcohol on the HPA axis, such as the ability of a first exposure to this drug during adolescence, to permanently blunt neuroendocrine responses to subsequent exposure of the drug. In view of the role played by CRF in addiction, it is likely that a better understanding of the mechanisms through which this drug stimulates the HPA axis may lead to the development of new therapies used in the treatment of alcohol abuse, including clinically relevant CRF antagonists. © 2014.