Joerg Breustedt

Publications (2)21.64 Total impact

• Source

  Available from: Benjamin R Rost

  Article: Activation of metabotropic GABA receptors increases the energy barrier for vesicle fusion.

  Benjamin R Rost, Patrick Nicholson, Gudrun Ahnert-Hilger, Andreas Rummel, Christian Rosenmund, Joerg Breustedt, Dietmar Schmitz
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  ABSTRACT: Neurotransmitter release from presynaptic terminals is under the tight control of various metabotropic receptors. We report here that in addition to the regulation of Ca(2+) channel activity, metabotropic GABA(B) receptors (GABA(B)Rs) at murine hippocampal glutamatergic synapses utilize an inhibitory pathway that directly targets the synaptic vesicle release machinery. Acute application of the GABA(B)R agonist baclofen rapidly and reversibly inhibits vesicle fusion, which occurs independently of the SNAP-25 C-terminus. Using applications of hypertonic sucrose solutions, we find that the size of the readily releasable pool remains unchanged by GABA(B)R activation, but the sensitivity of primed vesicles to hypertonic stimuli appears lowered as the response amplitudes at intermediate sucrose concentrations are smaller and release kinetics are slowed. These data show that presynaptic GABA(B)Rs can inhibit neurotransmitter release directly by increasing the energy barrier for vesicle fusion.
  Journal of Cell Science 08/2011; 124(Pt 18):3066-73. · 6.11 Impact Factor
• Article: Presynaptic kainate receptors impart an associative property to hippocampal mossy fiber long-term potentiation.

  Dietmar Schmitz, Jack Mellor, Joerg Breustedt, Roger A Nicoll
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  ABSTRACT: Hippocampal mossy fiber synapses show an unusual form of long-term potentiation (LTP) that is independent of NMDA receptor activation and is expressed presynaptically. Using receptor antagonists, as well as receptor knockout mice, we found that presynaptic kainate receptors facilitate the induction of mossy fiber long-term potentiation (LTP), although they are not required for this form of LTP. Most importantly, these receptors impart an associativity to mossy fiber LTP such that activity in neighboring mossy fiber synapses, or even associational/commissural synapses, influences the threshold for inducing mossy fiber LTP. Such a mechanism greatly increases the computational power of this form of plasticity.
  Nature Neuroscience 11/2003; 6(10):1058-63. · 15.53 Impact Factor