Supporting Online Material Materials and Methods Figs. S1 and S2 Tables S1 and S2 References Combined Analog and Action Potential Coding in Hippocampal Mossy Fibers

In the mammalian cortex, it is generally assumed that the output information of neurons is encoded in the number and the timing of action potentials. Here, we show, by using direct patchclamp recordings from presynaptic hippocampal mossy fiber boutons, that axons transmit analog signals in addition to action potentials. Excitatory presynaptic potentials result from subthreshold dendritic synaptic inputs, which propagate several hundreds of micrometers along the axon and modulate action potential–evoked transmitter release at the mossy fiber–CA3 synapse. This combined analog and action potential coding represents an additional mechanism for information transmission in a major hippocampal pathway.

[1]  G. G. Stokes.  "J." , 1890, The New Yale Book of Quotations.

[2]  Impulse-coded and analog signaling in single mechanoreceptor neurons. , 1982, Science.

[3]  E. Garcı́a-Austt,et al.  In vivo intracellular analysis of rat dentate granule cells , 1990, Brain Research.

[4]  K J Staley,et al.  Membrane properties of dentate gyrus granule cells: comparison of sharp microelectrode and whole-cell recordings. , 1992, Journal of neurophysiology.

[5]  M. Jackson,et al.  Passive current flow and morphology in the terminal arborizations of the posterior pituitary. , 1993, Journal of neurophysiology.

[6]  C. Koch,et al.  Recurrent excitation in neocortical circuits , 1995, Science.

[7]  Paul Antoine Salin,et al.  Distinct short-term plasticity at two excitatory synapses in the hippocampus. , 1996, Proceedings of the National Academy of Sciences of the United States of America.

[8]  B. McNaughton,et al.  Theta phase precession in hippocampal neuronal populations and the compression of temporal sequences , 1996, Hippocampus.

[9]  S. Laughlin,et al.  The rate of information transfer at graded-potential synapses , 1996, Nature.

[10]  A. S. French,et al.  Information processing by graded-potential transmission through tonically active synapses , 1996, Trends in Neurosciences.

[11]  A. S. French,et al.  The Efficiency of Sensory Information Coding by Mechanoreceptor Neurons , 1997, Neuron.

[12]  G. Buzsáki,et al.  Feed‐forward and feed‐back activation of the dentate gyrus in vivo during dentate spikes and sharp wave bursts , 1998, Hippocampus.

[13]  T. Gao,et al.  Transient neurophysiological changes in CA3 neurons and dentate granule cells after severe forebrain ischemia in vivo. , 1998, Journal of neurophysiology.

[14]  G Buzsáki,et al.  GABAergic Cells Are the Major Postsynaptic Targets of Mossy Fibers in the Rat Hippocampus , 1998, The Journal of Neuroscience.

[15]  P. Jonas,et al.  Dynamic Control of Presynaptic Ca2+ Inflow by Fast-Inactivating K+ Channels in Hippocampal Mossy Fiber Boutons , 2000, Neuron.

[16]  R. Nicoll,et al.  Presynaptic Kainate Receptor Mediation of Frequency Facilitation at Hippocampal Mossy Fiber Synapses , 2001, Science.

[17]  D. Wilkin,et al.  Neuron , 2001, Brain Research.

[18]  Jörg R P Geiger,et al.  Timing and Efficacy of Ca2+ Channel Activation in Hippocampal Mossy Fiber Boutons , 2002, The Journal of Neuroscience.

[19]  Ronald L Calabrese,et al.  Modulation of Spike-Mediated Synaptic Transmission by Presynaptic Background Ca2+ in Leech Heart Interneurons , 2003, The Journal of Neuroscience.

[20]  A. Grinvald,et al.  Interaction of sensory responses with spontaneous depolarization in layer 2/3 barrel cortex , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[21]  P. Katz,et al.  Synaptic Gating: The Potential to Open Closed Doors , 2003, Current Biology.

[22]  P. Jonas,et al.  A large pool of releasable vesicles in a cortical glutamatergic synapse , 2003, Proceedings of the National Academy of Sciences of the United States of America.

[23]  D. Kullmann,et al.  GABAA Receptors at Hippocampal Mossy Fibers , 2003, Neuron.

[24]  Christoph Schmidt-Hieber,et al.  Enhanced synaptic plasticity in newly generated granule cells of the adult hippocampus , 2004, Nature.

[25]  Gautam B. Awatramani,et al.  Modulation of Transmitter Release by Presynaptic Resting Potential and Background Calcium Levels , 2005, Neuron.

[26]  宁北芳,et al.  疟原虫var基因转换速率变化导致抗原变异[英]／Paul H, Robert P, Christodoulou Z, et al//Proc Natl Acad Sci U S A , 2005 .

[27]  Peter Jonas,et al.  Presynaptic Action Potential Amplification by Voltage-Gated Na+ Channels in Hippocampal Mossy Fiber Boutons , 2005, Neuron.