Peter Jonas – författare

It is now widely accepted that glutamate is the major excitatory neurotrans- mitter in the mammalian central nervous system. The main criteria for accept- ing a molecule as a chemical transmitter appear to be fulfilled at several synapses: Glutamate mimics the action of the natural transmitter in the post- synaptic neuron (CURTIS et al. 1959), glutamate is present in presynaptic ele- ments (OTTERSEN and STORM-MATHISEN 1984), and glutamate is released from central neurons in an activity-dependent manner (BRADFORD 1970). The postsynaptic receptors that mediate the effects of glutamate are markedly diverse. Based on their activation by agonists that act more selec- tively than the natural transmitter itself, a-amino-3-hydroxy-5-methyl- isoxazolepropionate (AMPA) receptors, kainate receptors, and N-methyl-D- aspartate (NMDA) receptors can be distinguished. Molecular cloning has revealed additional structural diversity. To date, almost 20 glutamate receptor subunit genes have been identified, and an even larger number of splice vari- ants and edited versions are present in the mammalian brain. Analysis of synaptic transmission revealed that "the" excitatory synapse does not exist.Glutamatergic synapses in different circuitries differ substan- tially in their signaling properties, although they use the same transmitter. We have learned that cellular, subcellular, and molecular factors determine synap- tic function, and that glutamate receptor subunit diversity is of direct relevance in shaping the unique signaling properties of a glutamatergic synapse.

It is now widely accepted that glutamate is the major excitatory neurotrans- mitter in the mammalian central nervous system. The main criteria for accept- ing a molecule as a chemical transmitter appear to be fulfilled at several synapses: Glutamate mimics the action of the natural transmitter in the post- synaptic neuron (CURTIS et al. 1959), glutamate is present in presynaptic ele- ments (OTTERSEN and STORM-MATHISEN 1984), and glutamate is released from central neurons in an activity-dependent manner (BRADFORD 1970). The postsynaptic receptors that mediate the effects of glutamate are markedly diverse. Based on their activation by agonists that act more selec- tively than the natural transmitter itself, a-amino-3-hydroxy-5-methyl- isoxazolepropionate (AMPA) receptors, kainate receptors, and N-methyl-D- aspartate (NMDA) receptors can be distinguished. Molecular cloning has revealed additional structural diversity. To date, almost 20 glutamate receptor subunit genes have been identified, and an even larger number of splice vari- ants and edited versions are present in the mammalian brain. Analysis of synaptic transmission revealed that "the" excitatory synapse does not exist.Glutamatergic synapses in different circuitries differ substan- tially in their signaling properties, although they use the same transmitter. We have learned that cellular, subcellular, and molecular factors determine synap- tic function, and that glutamate receptor subunit diversity is of direct relevance in shaping the unique signaling properties of a glutamatergic synapse.

rd This volume contains papers written by the participants of the 3 Workshop on Operator Theory in Krein spaces and Nonlinear Eigenvalue Problems, held at the Technische Universit. at Berlin, Germany, December 12 to 14, 2003. The workshop covered topics from spectral, perturbation and extension t- ory of linear operators in Krein spaces. They included generalized Nevanlinna functions and related classes of functions, boundary value problems for di?erential operators, spectral problems for matrix polynomials, and perturbation problems forsecondorderevolutionequations.Alltheseproblemsarere?ectedinthepresent volume. The workshop was attended by 46 participants from 12 countries. It is a pleasure to acknowledge the substantial ?nancial support received from the - Research Training Network HPRN-CT-2000-00116 "Analysis and Operators" by the European Community, - DFG-Forschungszentrum MATHEON "Mathematik fur .. Schlussel- .. technologien", - Institute of Mathematics of the Technische Universit. at Berlin. We would also like to thank Petra Grimberger for her great help.Last but not least, special thanks are due to Jussi Behrndt, Christian Mehl and Carsten Trunk for their excellent workin the organisationof the workshopand the preparationof this volume. Without their assistance the workshop might not have taken place. The Editors Operator Theory: Advances and Applications, Vol. 162, 1-17 c 2005 Birkh. auser Verlag Basel/Switzerland Partial Non-stationary Perturbation Determinants for a Class of J-symmetric Operators Vadim Adamyan, Peter Jonas and Heinz Langer Abstract. We consider the partial non-stationary perturbation determinant (1) itA ?itH ? (t):=det e P e ,t? R.