Compartmentalized and binary behavior of terminal dendrites in hippocampal pyramidal neurons.
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 occurred 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.
Wei
D S
DS
Departments of Neurology, University of Maryland School of Medicine, Baltimore, MD 21201, USA.
Mei
Y A
YA
Bagal
A
A
Kao
J P
JP
Thompson
S M
SM
Tang
C M
CM
D015763:2-Amino-5-phosphonovalerate / Q000494:pharmacology; D000200:Action Potentials; D000818:Animals; D002104:Cadmium / Q000494:pharmacology; D002118:Calcium / Q000378:metabolism; D015220:Calcium Channels / Q000378:metabolism; D020013:Calcium Signaling; D002586:Cesium / Q000494:pharmacology; D003712:Dendrites / Q000502:physiology*; D004533:Egtazic Acid / Q000031:analogs & derivatives / Q000494:pharmacology; D005971:Glutamates; D006624:Hippocampus / Q000166:cytology* / Q000502:physiology; D008027:Light; D009924:Organ Culture Techniques; D018408:Patch-Clamp Techniques; D010782:Photolysis; D017966:Pyramidal Cells / Q000187:drug effects / Q000502:physiology* / Q000648:ultrastructure; D011810:Quinoxalines / Q000494:pharmacology; D051381:Rats; D018091:Receptors, AMPA / Q000378:metabolism; D016194:Receptors, N-Methyl-D-Aspartate / Q000378:metabolism; D013779:Tetrodotoxin / Q000494:pharmacology
C102508:(carboxy-2-nitrobenzyl)glutamic acid; D015220:Calcium Channels; D005971:Glutamates; D011810:Quinoxalines; D018091:Receptors, AMPA; D016194:Receptors, N-Methyl-D-Aspartate; D002104:Cadmium; C062865:2,3-dioxo-6-nitro-7-sulfamoylbenzo(f)quinoxaline; D002586:Cesium; D013779:Tetrodotoxin; D004533:Egtazic Acid; D015763:2-Amino-5-phosphonovalerate; C025603:1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid; D002118:Calcium