More Accurate Models of Neurons with Dendritic Trees

The morphology of Golgi-impregnated thalamic neurons was investigated quantitatively. In particular, it was sought to test whether the dendritic bifurcations can be described by the scaling law (d0)n=(d1)n+(d2)nwith a single value of the diameter exponent n. Here d0 is the diameter of the parent branch, d1 and d2 are the diameters of the two daughter branches. Neurons from two functionally distinct regions were compared: the somatosensory ventrobasal complex (VB) and its nociceptive ventral periphery (VBvp). It is shown that for the neuronal trees studied in both regions, the scaling law was fulfilled. The diameter exponent n, however, was not a constant. It increased from n=1.76 for the 1st order branches to n=3.92 for the 7th order branches of neurons from both regions. These findings suggest that more than one simple intrinsic rule is involved in the neuronal growth process, and it is assumed that the branching ratio d0/d1 is not required to be encoded genetically. Furthermore, the results support the concept of the dendritic trees having a statistically identical topology in neurons of VB and VBvp and thus may be regarded as integrative modules.

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Structure of human auditory cortex. III. Statistical analysis of dendritic trees

Brain Research ◽

10.1016/0006-8993(82)90055-5 ◽

1982 ◽

Vol 249 (2) ◽

pp. 211-221 ◽

Cited By ~ 54

Author(s):

H.L. Seldon

Keyword(s):

Statistical Analysis ◽

Auditory Cortex ◽

Dendritic Trees ◽

Human Auditory Cortex

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A simple vector implementation of the Laplace-transformed cable equations in passive dendritic trees

Biological Cybernetics ◽

10.1007/bf00203133 ◽

1992 ◽

Vol 68 (1) ◽

pp. 15-21 ◽

Cited By ~ 11

Author(s):

Jaap van Pelt

Keyword(s):

Dendritic Trees

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Discrimination of Phase-Coded Spike Trains by Silicon Neurons with Artificial Dendritic Trees

Computational Neuroscience ◽

10.1007/978-1-4757-9800-5_25 ◽

1997 ◽

pp. 153-157

Author(s):

David P. M. Northmore ◽

John G. Elias

Keyword(s):

Spike Trains ◽

Dendritic Trees ◽

Silicon Neurons

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Structure-function relationships in the primate superior colliculus. I. Morphological classification of efferent neurons

Journal of Neurophysiology ◽

10.1152/jn.1988.60.1.232 ◽

1988 ◽

Vol 60 (1) ◽

pp. 232-262 ◽

Cited By ~ 138

Author(s):

A. K. Moschovakis ◽

A. B. Karabelas ◽

S. M. Highstein

Keyword(s):

Superior Colliculus ◽

Medium Size ◽

Cerebral Peduncle ◽

Parent Cell ◽

Morphological Classification ◽

Dendritic Trees ◽

Efferent Neurons ◽

Recurrent Collaterals ◽

Stimulation Of

1. Neurons in the superior colliculus (SC) of anesthetized paralyzed squirrel monkeys were injected intracellularly with horseradish peroxidase (HRP) to establish a morphological classification of tectal efferent neurons in this species. These neurons were physiologically identified by their antidromic responses following stimulation of the contralateral predorsal bundle or SC. These cells also responded with postsynaptic potentials to stimulation of the ipsilateral substantia nigra and cerebral peduncle and the contralateral tectum. 2. Quantitative light microscopic analysis of the somatodendritic profiles and axonal trajectories of 27 recovered cells revealed the existence of three major groups of tectal efferent neurons: L (n = 7), X (n = 8), and T (n = 12). 3. L neurons are small or medium size cells with relatively elaborate dendritic trees and are located mainly in the superficial layers of the SC. They participate in the ipsilateral descending and dorsal ascending tectofugal bundles. Intrinsic collaterals of L axons deploy a large number of boutons both near the parent cell body and more ventrally within the deeper tectal layers. 4. X neurons are mostly large in size and multipolar in shape with relatively complex dendritic trees. Their cell bodies are situated mainly in the stratum griseum intermedium and occasionally in the stratum opticum. Axons of X neurons participate in the crossed descending and ipsilateral ventral ascending projections of the SC. In addition, the axonal system of about half of the X neurons includes recurrent collaterals. 5. T neurons are located mainly in the ventral stratum opticum and the dorsal stratum griseum intermedium. They have small or medium-sized, trapezoid or ovoid cell bodies and relatively simple radiating or vertical dendritic trees. Their axons usually participate in two of the major tectofugal bundles besides providing a commissural component and recurrent collaterals. 6. Morphological details revealed in the present study support the notion that distinct tectofugal axonal systems originate from efferent neurons of the primate SC that differ both as to their location in the tectum as well as the appearance of their somata and dendritic trees. The resulting morphological classification of tectal efferent cells provides a framework for the analysis of tectal function in terms of populations of identified neurons.

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