Compartmentalized and Binary Behavior of Terminal Dendrites in Hippocampal Pyramidal Neurons

• Published in: Science (American Association for the Advancement of Science) Vol. 293; no. 5538; pp. 2272 - 2275
• Main Authors: Wei, Dong-Sheng, Mei, Yan-Ai, Bagal, Ashish, Joseph P. Y. Kao, Thompson, Scott M., Tang, Chan-Min
• Format: Journal Article
• Language: English
• Published: Washington, DC American Society for the Advancement of Science 21-09-2001; American Association for the Advancement of Science; The American Association for the Advancement of Science
• Subjects: 2-Amino-5-phosphonovalerate - pharmacology; Action Potentials; Analysis; Animals; Biological and medical sciences; Branches; Cadmium - pharmacology; Calcium; Calcium - metabolism; Calcium Channels - metabolism; Calcium Signaling; Cell research; Central nervous system; Cesium; Cesium - pharmacology; Cytological research; Cytology; Dendrites; Dendrites - physiology; Depolarization; Egtazic Acid - analogs & derivatives; Egtazic Acid - pharmacology; Electrophysiology; Feedback (Response); Fundamental and applied biological sciences. Psychology; Glutamates; Hippocampus - cytology; Hippocampus - physiology; Kinetics; Lasers; Light; Neurology; Neurons; Organ Culture Techniques; Patch-Clamp Techniques; Photolysis; Pyramidal Cells - drug effects; Pyramidal Cells - physiology; Pyramidal Cells - ultrastructure; Quinoxalines - pharmacology; Rats; Receptors, AMPA - metabolism; Receptors, N-Methyl-D-Aspartate - metabolism; Stimuli; Tetrodotoxin - pharmacology; Tree trunks; Vertebrates: nervous system and sense organs; United States; Calcium; Rat; Rodentia; Central nervous system; Electrophysiology; Ionic channel; Glutamate; Dendrite; Vertebrata; Mammalia; Pyramidal neuron; Hippocampus; Brain (vertebrata)
• ISSN: 0036-8075; 1095-9203
• DOI: 10.1126/science.1061198

The dendritic arbor of pyramidal neurons is not a monolithic structure. We show here that the excitability of terminal apical dendrites differs from that of the apical trunk. In response to fluorescence-guided focal photolysis of caged glutamate, individual terminal apical dendrites generated cadmium-sensitive all-or-none responses that were subthreshold for somatic action potentials. Calcium transients produced by all-or-none responses were not restricted to the sites of photolysis, but occured throughout individual distal dendritic compartments, indicating that electrogenesis is mediated primarily by voltage-gated calcium channels. Compartmentalized and binary behavior of parallel-connected terminal dendrites can greatly expand the computational power of a single neuron.