A5087163372- Cellular Mechanics and Interactions
- Hearing, Cochlea, Tinnitus, Genetics
- Animal Vocal Communication and Behavior
- Nonlinear Dynamics and Pattern Formation
- Marine animal studies overview
- Advanced Materials and Mechanics
- Neural dynamics and brain function
- Hearing Loss and Rehabilitation
- Microtubule and mitosis dynamics
- Thermal Radiation and Cooling Technologies
- Plant Molecular Biology Research
- stochastic dynamics and bifurcation
- Acoustic Wave Phenomena Research
- Developmental Biology and Gene Regulation
- Micro and Nano Robotics
- Bat Biology and Ecology Studies
- Cardiomyopathy and Myosin Studies
- Tissue Engineering and Regenerative Medicine
- Neurobiology and Insect Physiology Research
- Polydiacetylene-based materials and applications
- 3D Printing in Biomedical Research
- Advanced Fluorescence Microscopy Techniques
- Force Microscopy Techniques and Applications
- Noise Effects and Management
- Vestibular and auditory disorders
Centre for Genomic Regulation
2014-2023
Universitat Pompeu Fabra
2014-2017
Max Planck Institute for the Physics of Complex Systems
2008-2013
Max Planck Society
2009-2012
VPIphotonics (Germany)
2010
Animal cell shape is controlled primarily by the actomyosin cortex, a thin cytoskeletal network that lies directly beneath plasma membrane. The cortex regulates morphology controlling cellular mechanical properties, which are determined structure and geometry. In particular, thickness expected to influence mechanics. However, near resolution limit of light microscope, making studies relating challenging. To overcome this, we developed an assay measure in live cells, combining confocal...
Single and collective cellular oscillations driven by the actomyosin cytoskeleton have been observed in numerous biological systems. Here, we propose that these can be accounted for a generic oscillator model of material turning over contracting against an elastic element. As example, show during dorsal closure Drosophila embryo, experimentally changes concentration oscillatory cell shape can, indeed, captured dynamic equations studied here. We also investigate dynamics ensemble such...
During epithelial contraction, cells generate forces to constrict their surface and, concurrently, fine-tune the length of adherens junctions ensure force transmission. While many studies have focused on understanding generation, little is known how junctional controlled. Here, we show that, during amnioserosa contraction in Drosophila dorsal closure, reduce coordination with shrinkage apical cell area, maintaining a nearly constant straightness. We reveal that straightness and integrity...
During development, cell-generated forces induce tissue-scale deformations to shape the organism [1Lecuit T. Lenne P.F. Munro E. Force generation, transmission, and integration during cell tissue morphogenesis.Annu. Rev. Cell Dev. Biol. 2011; 27: 157-184Crossref PubMed Scopus (366) Google Scholar, 2Heisenberg C.P. Bellaïche Y. Forces in morphogenesis patterning.Cell. 2013; 153: 948-962Abstract Full Text PDF (700) Scholar]. The pattern extent of these depend not solely on temporal spatial...
The vertebrate inner ear possesses an active process that provides nonlinear amplification of mechanical stimuli. A candidate for this is hair bundle mechanics observed, instance, cells the bullfrog's sacculus. Hair bundles in various organs are coupled by overlying membranes. Using a stochastic description dynamics, we study consequences elastic coupling on properties amplification. We report collective effects arrays can enhance gain and sharpness frequency tuning as compared with...
We employ a Hodgkin-Huxley type model of basolateral ionic currents in bullfrog saccular hair cells to study the genesis spontaneous voltage oscillations and their role shaping response cell external mechanical stimuli. Consistent with recent experimental reports, we find that dynamics can be categorized using conductance parameters calcium activated potassium, inward rectifier mechano-electrical transduction currents. The is demonstrated exhibit broad spectrum autonomous rhythmic activity,...
The vertebrate ear benefits from nonlinear mechanical amplification to operate over a vast range of sound intensities. amplificatory process is thought emerge active force production by sensory hair cells. mechano-sensory bundle that protrudes the apical surface each cell can oscillate spontaneously and function as frequency-selective, amplifier. Intrinsic fluctuations, however, jostle response single weak stimuli seriously limit amplification. Most bundles are mechanically coupled overlying...
ABSTRACT Collective cell rotations are widely used during animal organogenesis. Theoretical and in vitro studies have conceptualized rotating cells as identical rigid-point objects that stochastically break symmetry to move monotonously perpetually within an inert environment. However, it is unclear whether this notion can be extrapolated a natural context, where ephemeral heterogeneous cellular cohorts interact with active epithelium. In zebrafish neuromasts, nascent sibling hair invert...
Nonlinear compression of periodic signals is a key feature the active amplifier in inner ear organs all vertebrates. Different exponents alpha(0) [-0.88,-0.5] sensitivity vs forcing amplitude |chi| approximately f(alpha(0)) have been observed. Here we calculate analytically local exponent for generic oscillator, normal form Hopf bifurcation driven by noise and signal. For weak sufficient distance from on unstable side, may be close to -1 moderate amplitudes beyond linear response. Such...
A deterministic system that operates in the vicinity of a Hopf bifurcation can be described by single equation complex variable, called normal form. Proximity to ensures on stable side (i.e. where fixed point exists), linear-response function is peaked at frequency characteristic oscillatory instability. Fluctuations, which are present many systems, conceal and lead noisy oscillations. Spontaneous hair bundle oscillations sensory cells from vertebrate ear provide an instructive example such...
We study the dynamics of oscillatory hair bundles which are coupled elastically in their deflection variable and subject to noise. present a stochastic description capturing bundles' mean field. In particular, presented derivation elucidates origin previously described noise reduction by coupling. By comparison simulations approximate full system, we verify our results. Furthermore, demonstrate that specific type coupling considered implies coupling-induced changes beyond mere reduction.
Abstract During development, cell-generated forces induce tissue-scale deformations to shape the organism. Here, we present a method that allows quantitatively relate such spatially localized and measure mechanical properties of epithelia in vivo . Our approach is based on application controlled microparticles embedded individual cells an embryo. Combining measurements bead displacement with analysis induced deformation fields continuum mechanics framework, can quantify tissue material...
Sensory hair cells in auditory and vestibular organs rely on active mechanisms to achieve high sensitivity frequency selectivity with respect weak stimuli. Self-sustained oscillations occur two very different levels. First, the mechano-sensory bundle itself can undergo spontaneous mechanical oscillations. Second, self-sustained electric voltage across membrane of cell have been documented inner ear lower vertebrates. The functional significance these is currently unknown. We used a...
Single and collective cellular oscillations involving the actomyosin cytoskeleton have been observed in numerous biological systems. We show here that a generic model of contractile material, which is turning over contracts against an elastic element, exhibits spontaneous oscillations. Such can thus account for shape amnioserosa cells during dorsal closure Drosophila embryo. investigate dynamics ensemble such oscillators relative contribution viscous friction losses yield different regimes...
The mammalian cochlea has been recognized to act as an active and nonlinear amplifier. Previously, a generic description in terms of critical oscillators explored the Fourier domain. Here, we discuss generalized variant this model formulated time As first step, verify that model's response periodic stimulation is similar original Fourier‐domain model. domain offers possibility study effects static dynamic noise sources on spectral statistics spontaneous evoked otoacoustic emissions.
or> Meeting abstracts - A single PDF containing all in this Supplement is available here . http://www. biomedcentral.co m/content/pdf/14 71-2202 -10-S1-info.pdf