The following paper is available at
http://lnc.usc.edu/library/Polsky_Mel_Schiller04.pdf
Polsky, A., Mel B.W. & Schiller, J. (2004) Computational subunits in
thin dendrites of pyramidal cells. Nature Neuroscience, 7, 621-627.
Abstract
The thin basal and oblique dendrites of cortical pyramidal neurons
receive most of the synaptic inputs from cells, but their integrative
properties remains uncertain. Previous studies have most often reported
global linear or sublinear summation. An alternative view, supported by
biophysical modeling studies, holds that thin dendrites provide a layer
of independent computational ‘subunits’ that sigmoidally modulate their
inputs prior to global summation. To distinguish these possibilities, we
combined confocal imaging and dual-site focal synaptic stimulation of
identified thin dendrites in rat neocortical pyramidal neurons. We found
that nearby inputs on the same branch summed sigmoidally, whereas widely
separated inputs or inputs to different branches summed linearly. This
strong spatial compartmentalization effect is incompatible with a global
summation rule and provides the first experimental support for a
two-layer `neural network' model of pyramidal neuron thin-branch
integration. Our findings could have important implications for the
computing and memory-related functions of cortical tissue.
-Bartlett
--Bartlett W. Mel, Assoc Prof Biomed Engin, Neurosci Grad Prog USC, BME Dept, MC 1451, Los Angeles, CA 90089 mel@usc.edu, http://LNC.usc.edu voice: (213)740-0334, lab: -3397, fax: -0343 fedex: 3650 McClintock Ave, 500 Olin Hall
|
Home Login Meetings Courses Belgium Maillist Credits Servers Links Archive
Please send comments and suggestions to
Mike Wijnants. |
|
Page last updated on © BBF 1998 all rights reserved |