scholarly journals Synaptic Integration Gradients in Single Cortical Pyramidal Cell Dendrites

Neuron ◽  
2011 ◽  
Vol 69 (5) ◽  
pp. 885-892 ◽  
Author(s):  
Tiago Branco ◽  
Michael Häusser
Author(s):  
Oleg V. Favorov ◽  
Joseph T. Hester ◽  
Douglas G. Kelly ◽  
Dan Ryder ◽  
Mark Tommerdahl

1999 ◽  
Vol 16 (1) ◽  
pp. 65-79 ◽  
Author(s):  
DAVID M. SENSEMAN

The spatiotemporal structure of cortical activity evoked by diffuse light flashes was investigated in an isolated eyecup-brain preparation of the pond turtle, Pseudemys scripta. By combining a photomicroscopic image of the preparation with voltage-sensitive dye signals recorded by a 464-element photodiode array, the spread of depolarization within different cortical areas could be directly visualized with millisecond temporal resolution. Diffuse stimulation of the contralateral eyecup initially depolarized the visual cortex at the junction between its lateral and medial divisions in a small area rostral of the ventricular eminence. From this point, the depolarization spread at different velocities (10–100 μm/ms) depending upon the direction of travel. Since the initial depolarization was always in the rostral pole, the largest spread invariably occurred in a rostral → caudal direction. Within the confines of the medial visual cortex, depolarization spread at a constant velocity but slowed after entering the adjoining medial cortex. Increasing the stimulus illuminance increased the velocity of spread. Rostrocaudal spread of depolarization was also observed in response to electrical stimulation of the geniculocortical pathway and by direct focal stimulation of the cortical sheet. These data suggest that excitatory connections between pyramidal cell clusters play a prominent role in the initial activation of the cortex by diffuse retinal stimulation.


2018 ◽  
Author(s):  
Toviah Moldwin ◽  
Idan Segev

AbstractThe perceptron learning algorithm and its multiple-layer extension, the backpropagation algorithm, are the foundations of the present-day machine learning revolution. However, these algorithms utilize a highly simplified mathematical abstraction of a neuron; it is not clear to what extent real biophysical neurons with morphologically-extended nonlinear dendritic trees and conductance-based synapses could realize perceptron-like learning. Here we implemented the perceptron learning algorithm in a realistic biophysical model of a layer 5 cortical pyramidal cell. We tested this biophysical perceptron (BP) on a memorization task, where it needs to correctly binarily classify 100, 1000, or 2000 patterns, and a generalization task, where it should discriminate between two “noisy” patterns. We show that the BP performs these tasks with an accuracy comparable to that of the original perceptron, though the memorization capacity of the apical tuft is somewhat limited. We concluded that cortical pyramidal neurons can act as powerful classification devices.


1996 ◽  
Vol 141 (2) ◽  
pp. 269-279 ◽  
Author(s):  
N.G. Harris ◽  
J.P. McAllister II ◽  
J.M. Conaughty ◽  
H.C. Jones

2018 ◽  
Vol 56 (7) ◽  
pp. 4960-4979 ◽  
Author(s):  
Alexander Jack ◽  
Mohammad I. K. Hamad ◽  
Steffen Gonda ◽  
Sebastian Gralla ◽  
Steffen Pahl ◽  
...  

2006 ◽  
Vol 17 (1) ◽  
pp. 238-249 ◽  
Author(s):  
I Ballesteros-Yanez ◽  
E Ambrosio ◽  
R Benavides-Piccione ◽  
J Perez ◽  
I Torres ◽  
...  

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