Dependence of EPSP Efficacy on Synapse Location in Neocortical Pyramidal Neurons

• Published in: Science (American Association for the Advancement of Science) Vol. 295; no. 5561; pp. 1907 - 1910
• Main Authors: Williams, Stephen R., Stuart, Greg J.
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 08.03.2002; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: Action Potentials; Animals; Axons - physiology; Biological and medical sciences; Brain; Cell membranes; Cells; Central nervous system; Dendrites; Dendrites - physiology; Electrophysiology; Excitatory Postsynaptic Potentials; Fundamental and applied biological sciences. Psychology; Kinetics; Neocortex; Neocortex - cytology; Neocortex - physiology; Neurology; Neurons; Neuroscience; Patch-Clamp Techniques; Pyramidal Cells - physiology; Rats; Rats, Wistar; Synapses; Synapses - physiology; Synaptic Transmission; Time windows; Transcriptional regulatory elements; Vertebrates: nervous system and sense organs; United States; Electrophysiology; Cerebral cortex; Pyramidal neuron; Excitatory postsynaptic potential; Central nervous system; Brain (vertebrata)
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1067903

Neurons receive thousands of synaptic inputs throughout elaborate dendritic trees. Here we determine the somatic impact of excitatory postsynaptic potentials (EP-SPs) generated at known dendritic sites in neocortical pyramidal neurons. As inputs became more distal, somatic EPSP amplitude decreased, whereas use-dependent depression increased. Despite marked attenuation (>40-fold), when coactivated within a narrow time window (∼10 milliseconds), distal EPSPs could directly influence action potential output following dendritic spike generation. These findings reveal that distal EPSPs are ineffective sources of background somatic excitation, but through coincidence detection have a powerful transient signaling role.