| The spread of biochemical signals is not only important to sustain the normal metabolic activity of neurons but it is crucial for neuron-specific function such as synaptic plasticity. In this talk I will present experimental and computational results showing that the intricate structure of neurons severely affects the spread of chemical signals. I will address three specific examples spanning a wide range of spatial scales, from diffusion of biochemical signals in dendritic trees to molecular aggregation in synapses. At the largest spatial scale, I will show how the structure of dendritic trees affects diffusion of molecules in the cytosol. In this case we find that dendritic spines act as molecular traps for molecules moving along the dendrites of cerebellar Purkinje and hippocampal pyramidal cells. The second example shows initial evidence that the cytosolic structure of neurons, composed of cytoskeleton and macro-molecules, is different between dendrites and soma. I will introduce a relatively new technique called fluorescence correlation spectroscopy that we use to measure the diffusional environment of cells at sub-microscopic levels in combination of two-photon microscopy. The third example will be modeling work suggesting a strong influence of the molecular structure of the post-synaptic density in determining the homeostasis of glutamate receptors in synapses. I will end by discussing the consequence of all these mechanisms in the activation of long term depression, a cellular model of learning and memory in Purkinje cell synapses.
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Global
COE Special Seminar |
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Date： |
February
23, 2009(Mon) 15:00～16:00 |
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Place： |
Faculty
of Medical Experimental Research Bldg. 13F, room 1303 |
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Host： |
Tanaka Keiko(ktanaka AT bi.s.u-tokyo.ac.jp) |
Kawasaki Hiroshi(kawasaki AT m.u-tokyo.ac.jp) |
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