Conditional dendritic spike propagation following distal synaptic activation of hippocampal CA1 pyramidal neurons.
The perforant-path projection to the hippocampus forms synapses in the apical tuft of CA1 pyramidal neurons. We used computer modeling to examine the function of these distal synaptic inputs, which led to three predictions that we confirmed in experiments using rat hippocampal slices. First, activation of CA1 neurons by the perforant path is limited, a result of the long distance between these inputs and the soma. Second, activation of CA1 neurons by the perforant path depends on the generation of dendritic spikes. Third, the forward propagation of these spikes is unreliable, but can be facilitated by modest activation of Schaffer-collateral synapses in the upper apical dendrites. This 'gating' of dendritic spike propagation may be an important activation mode of CA1 pyramidal neurons, and its modulation by neurotransmitters or long-term, activity-dependent plasticity may be an important feature of dendritic integration during mnemonic processing in the hippocampus.
Jarsky
Tim
T
Institute for Neuroscience, Department of Neurobiology and Physiology, Northwestern University, 2205 Tech Drive, Evanston, Illinois 60208, USA.
Roxin
Alex
A
Kath
William L
WL
Spruston
Nelson
N
D000200:Action Potentials / Q000502:physiology*; D000818:Animals; D003712:Dendrites / Q000502:physiology*; D006624:Hippocampus / Q000166:cytology / Q000502:physiology*; D017774:Long-Term Potentiation / Q000502:physiology; D036881:Long-Term Synaptic Depression / Q000502:physiology; D008297:Male; D008568:Memory / Q000502:physiology; D009433:Neural Inhibition / Q000502:physiology; D016571:Neural Networks, Computer; D009434:Neural Pathways / Q000502:physiology*; D018377:Neurotransmitter Agents / Q000378:metabolism; D009924:Organ Culture Techniques; D018408:Patch-Clamp Techniques; D019580:Perforant Pathway / Q000502:physiology; D017966:Pyramidal Cells / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D009435:Synaptic Transmission / Q000502:physiology*
D018377:Neurotransmitter Agents