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.
Alle
Henrik
H
Independent Hertie Research Group, Max Planck Institute for Brain Research, D-60528 Frankfurt, Germany.
Geiger
Jörg R P
JR
D018750:6-Cyano-7-nitroquinoxaline-2,3-dione / Q000494:pharmacology; D000200:Action Potentials; D000818:Animals; D020013:Calcium Signaling; D003712:Dendrites / Q000502:physiology; D018891:Dentate Gyrus / Q000166:cytology / Q000502:physiology*; D018691:Excitatory Amino Acid Antagonists / Q000494:pharmacology; D019706:Excitatory Postsynaptic Potentials; D066298:In Vitro Techniques; D008959:Models, Neurological; D019599:Mossy Fibers, Hippocampal / Q000502:physiology*; D009474:Neurons / Q000502:physiology*; D018408:Patch-Clamp Techniques; D051381:Rats; D017208:Rats, Wistar; D018091:Receptors, AMPA / Q000037:antagonists & inhibitors / Q000378:metabolism; D012044:Regression Analysis; D013569:Synapses / Q000502:physiology; D009435:Synaptic Transmission
D018691:Excitatory Amino Acid Antagonists; D018091:Receptors, AMPA; D018750:6-Cyano-7-nitroquinoxaline-2,3-dione