Sci. Signal., 11 August 2009
Neuroscience Fine Dendrites Fire Differently
Peter R. Stern
Science, AAAS, Cambridge CB2 1LQ, UK
The pyramidal neuron is the basic computational unit in the brain cortex. Its distal tuft dendrite is heavily innervated by horizontal fibers coursing through cortical layer 1, providing long-range corticocortical and thalamocortical associational input. Larkum et al. investigated whether the apical tuft dendrites of layer 5 neocortical pyramidal neurons, like basal dendrites, generate N-methyl-D-aspartate (NMDA) spikes using two-photon–guided direct dendritic recording, glutamate uncaging, and modeling. NMDA spikes could be evoked in the distal tuft dendrites, whereas Ca2+ spikes could be triggered at the bifurcation points. Block of the hyperpolarization-activated current enhanced these NMDA spikes. Thus, the generation of NMDA spikes is a general principle of thin, basal, and tuft dendrites.
M. E. Larkum, T. Nevian, M. Sandler, A. Polsky, J. Schiller, Synaptic integration in tuft dendrites of layer 5 pyramidal neurons: A new unifying principle. Science 325, 756–760 (2009). [Abstract] [Full Text]
Citation: P. R. Stern, Fine Dendrites Fire Differently. Sci. Signal. 2, ec270 (2009).
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