TY - JOUR
AB - Increasing evidence supports roles for the current mediated by hyperpolarization-activated cyclic nucleotide-gated (HCN) channels, I h, in hippocampal maturation and specifically in the evolving changes of intrinsic properties as well as network responses of hippocampal neurons. Here, we describe a novel developmental plasticity of HCN channel expression in axonal and presynaptic compartments: HCN1 channels were localized to axon terminals of the perforant path (the major hippocampal afferent pathway) of immature rats, where they modulated synaptic efficacy. However, presynaptic expression and functions of the channels disappeared with maturation. This was a result of altered channel transport to the axons, because HCN1 mRNA and protein levels in entorhinal cortex neurons, where the perforant path axons originate, were stable through adulthood. Blocking action potential firing in vitro increased presynaptic expression of HCN1 channels in the perforant path, suggesting that network activity contributed to regulating this expression. These findings support a novel developmentally regulated axonal transport of functional ion channels and suggest a role for HCN1 channel-mediated presynaptic I h in hippocampal maturation.
AU - Bender, Roland A
AU - Kirschstein, Timo
AU - Kretz, Oliver
AU - Brewster, Amy L
AU - Richichi, Cristina
AU - Rüschenschmidt, Christiane
AU - Ryuichi Shigemoto
AU - Beck,Heinz
AU - Frotscher, Michael
AU - Baram, Tallie Z
ID - 2671
IS - 17
JF - Journal of Neuroscience
TI - Localization of HCN1 channels to presynaptic compartments: Novel plasticity that may contribute to hippocampal maturation
VL - 27
ER -
TY - JOUR
AB - Hyperpolarization-activated cyclic nucleotide-modulated (HCN) "pacemaker" channel subunits are integral membrane proteins that assemble as tetramers to form channels in cardiac conduction tissue and nerve cells. Previous studies have suggested that the HCN2 and HCN4 channel isoforms physically interact when overexpressed in mammalian cells, but whether they are able to co-assemble and form functional channels remains unclear. The extent to which co-assembly occurs over self-assembly and whether HCN2-HCN4 heteromeric channels are formed in native tissue are not known. In this study, we show co-assembly of HCN2 and HCN4 in live Chinese hamster ovary cells using bioluminescence resonance energy transfer (BRET2), a novel approach for studying tetramerization of ion channel subunits. Together with results from electrophysiological and imaging approaches, the BRET2 data show that HCN2 and HCN4 subunits self-assemble and co-assemble with equal preference. We also demonstrate colocalization of HCN2 and HCN4 and a positive correlation of their intensities in the embryonic mouse heart using immunohistochemistry, as well as physical interactions between these isoforms in the rat thalamus by coimmunoprecipitation. Together, these data support the formation of HCN2-HCN4 heteromeric channels in native tissue.
AU - Whitaker, Gina M
AU - Angoli, Damiano
AU - Nazzari, Hamed
AU - Ryuichi Shigemoto
AU - Accili, Eric A
ID - 2672
IS - 31
JF - Journal of Biological Chemistry
TI - HCN2 and HCN4 isoforms self-assemble and co-assemble with equal preference to form functional pacemaker channels
VL - 282
ER -
TY - JOUR
AB - Excitatory synaptic transmission is inhibited by G protein coupled receptors, including the adenosine A1, GABAB, and metabotropic glutamate receptor 7. These receptors are present in nerve terminals where they reduce the release of glutamate through activating signaling pathways negatively coupled to Ca2+ channels and adenylyl cyclase. However, it is not clear whether these receptors operate in distinct subpopulations of nerve terminals or if they are co-expressed in the same nerve terminals, despite the functional consequences that such distributions may have on synaptic transmission. Applying Ca2+ imaging and immunocytochemistry, we show that these three G protein coupled receptors coexist in a subpopulation of cerebrocortical nerve terminals. The three receptors share an intracellular signaling pathway through which their inhibitory responses are integrated and coactivation of these receptors produced an integrated response. Indeed, this response was highly variable, from a synergistic response at subthreshold agonist concentrations to an occluded response at high agonist concentrations. The presence of multiple receptors in a nerve terminal could be responsible for the physiological effects of neurotransmitter spillover from neighboring synapses or alternatively, the co-release of transmitters by the same nerve terminal.
AU - Ladera, Carolina
AU - Godino, María D
AU - Martín, Ricardo J
AU - Luján, Rafael
AU - Ryuichi Shigemoto
AU - Ciruela, Francisco
AU - Torres, Magdalena
AU - Sánchez-Prieto, José
ID - 2673
IS - 6
JF - Journal of Neurochemistry
TI - The coexistence of multiple receptors in a single nerve terminal provides evidence for pre-synaptic integration
VL - 103
ER -
TY - CHAP
AU - László Erdös
ED - Gesztesy, Fritz
ED - Deift, Percy
ED - Galvez, Percy
ED - Perry, Peter
ED - Schlag, Wilhelm
ID - 2705
T2 - Spectral Theory and Mathematical Physics: a Festschrift in Honor of Barry Simon's 60th Birthday
TI - Recent developments in quantum mechanics with magnetic fields
VL - 76
ER -
TY - JOUR
AB - The time-dependent Gross-Pitaevskii equation describes the dynamics of initially trapped Bose-Einstein condensates. We present a rigorous proof of this fact starting from a many-body bosonic Schrödinger equation with a short-scale repulsive interaction in the dilute limit. Our proof shows the persistence of an explicit short-scale correlation structure in the condensate.
AU - László Erdös
AU - Schlein, Benjamin
AU - Yau, Horng-Tzer
ID - 2748
IS - 4
JF - Physical Review Letters
TI - Rigorous derivation of the Gross-Pitaevskii equation
VL - 98
ER -
TY - GEN
AB - We prove rigorously that the one-particle density matrix of three dimensional interacting Bose systems with a short-scale repulsive pair interaction converges to the solution of the cubic non-linear Schrödinger equation in a suitable scaling limit. The result is extended to k-particle density matrices for all positive integer k.
AU - László Erdös
AU - Schlein, Benjamin
AU - Yau, Horng-Tzer
ID - 2749
IS - 3
T2 - Inventiones Mathematicae
TI - Derivation of the cubic non linear Schrödinger equation from quantum dynamics of many body systems
VL - 167
ER -
TY - JOUR
AB - We consider random Schrödinger equations on ℝd for d ≥ 3 with a homogeneous Anderson-Poisson type random potential. Denote by λ the coupling constant and ψt the solution with initial data ψ0. The space and time variables scale as χ ≃λ-2-κ/2, t ≃λ-2-κ with 0 < kappa; < kappa;0(d). We prove that, in the limit λ → 0, the expectation of the Wigner distribution of ψt converges weakly to the solution of a heat equation in the space variable x for arbitrary L2 initial data. The proof is based on a rigorous analysis of Feynman diagrams. In the companion paper [10] the analysis of the non-repetition diagrams was presented. In this paper we complete the proof by estimating the recollision diagrams and showing that the main terms, i.e. the ladder diagrams with renormalized propagator, converge to the heat equation.
AU - László Erdös
AU - Salmhofer, Manfred
AU - Yau, Horng-Tzer
ID - 2750
IS - 1
JF - Communications in Mathematical Physics
TI - Quantum diffusion of the random Schrödinger evolution in the scaling limit II. The recollision diagrams
VL - 271
ER -
TY - JOUR
AB - We consider random Schrödinger equations on ℤd for d ≥ 3 with identically distributed random potential. Denote by λ the coupling constant and ψ t the solution with initial data ψ 0. The space and time variables scale as x ∼ λ -2-κ/2,t ∼ λ-2-κ with 0 < κ < κ0(d). We prove that, in the limit λ → 0, the expectation of the Wigner distribution of ψ t converges weakly to a solution of a heat equation in the space variable x for arbitrary L 2 initial data. The diffusion coefficient is uniquely determined by the kinetic energy associated to the momentum υ. This work is an extension to the lattice case of our previous result in the continuum [8,9]. Due to the non-convexity of the level surfaces of the dispersion relation, the estimates of several Feynman graphs are more involved.
AU - László Erdös
AU - Salmhofer, Manfred
AU - Yau, Horng-Tzer
ID - 2751
IS - 4
JF - Annales Henri Poincare
TI - Quantum diffusion for the Anderson model in the scaling limit
VL - 8
ER -
TY - JOUR
AB - We prove L p -bounds on the Fourier transform of measures μ supported on two dimensional surfaces. Our method allows to consider surfaces whose Gauss curvature vanishes on a one-dimensional submanifold. Under a certain non-degeneracy condition, we prove that μ ∧ ε L 4+β, β > 0, and we give a logarithmically divergent bound on the L 4-norm. We use this latter bound to estimate almost singular integrals involving the dispersion relation, e(p)= ∑13 [1-\cos p_j]} , of the discrete Laplace operator on the cubic lattice. We briefly explain our motivation for this bound originating in the theory of random Schrödinger operators.
AU - László Erdös
AU - Salmhofer, Manfred
ID - 2752
IS - 2
JF - Mathematische Zeitschrift
TI - Decay of the Fourier transform of surfaces with vanishing curvature
VL - 257
ER -
TY - GEN
AB - Pipe flow is a prominent example among the shear flows that undergo transition to turbulence without mediation by a linear instability of the laminar profile. Experiments on pipe flow, as well as plane Couette and plane Poiseuille flow, show that triggering turbulence depends sensitively on initial conditions, that between the laminar and the turbulent states there exists no intermediate state with simple spatial or temporal characteristics, and that turbulence is not persistent, i.e., it can decay again, if the observation time is long enough. All these features can consistently be explained on the assumption that the turbulent state corresponds to a chaotic saddle in state space. The goal of this review is to explain this concept, summarize the numerical and experimental evidence for pipe flow, and outline the consequences for related flows.
AU - Eckhardt, Bruno
AU - Schneider, Tobias M
AU - Björn Hof
AU - Westerweel, Jerry
ID - 2793
T2 - Annual Review of Fluid Mechanics
TI - Turbulence transition in pipe flow
VL - 39
ER -