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Morphological Changes in Pyramidal Cells of Mammalian Neocortex Associated with Increased Use

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L. T. Rutledge, C. Wright, J. Duncan · 1974

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Direct electrical brain stimulation changed neuron structure in cats, with more terminal branching and more spines in apical dendrites of the opposite cortex.

Plain English Summary

Summary written for general audiences

Researchers electrically stimulated cat brains daily for weeks and found that neurons on the opposite side of the brain grew more complex structures with increased branching and connections. This 1974 study interpreted the changes as evidence that increased use of specific pathways to the cerebral cortex produces postsynaptic growth in some cortical neurons.

Why This Matters

This 1974 study provides foundational evidence that electrical stimulation is associated with structural change in brain cells. The researchers used direct electrode stimulation rather than wireless EMF, so the exposure differs from today's EMF exposure concerns. The study found increased terminal branching and more spines on apical dendrites in cortex contralateral to the stimulated side, and the authors interpret these changes as evidence that increased use of specific pathways produces postsynaptic growth in some cortical neurons. The study stimulated cats with implanted electrodes, 20 trains of 2 seconds each per day for several weeks.

Figures from the Original Paper

Diagrams extracted from the original research document.

diagramPage 5 - AI-described figure: Fig. 1 illustrates measurements made on pyramidal cells other than spine counts, including soma-pia distance and dendritic branch details.
p. 5 of the original PDF
diagramPage 7 - AI-described figure: Fig. 2: Scale drawings of upper cortex pyramidal neurons showing dendritic branching and spine distribution.
p. 7 of the original PDF
chartPage 10 - Figure 3. Apical dendritic spine counts at three locations for trained and untrained animals.
p. 10 of the original PDF
Cite This Study
L. T. Rutledge, C. Wright, J. Duncan (1974). Morphological Changes in Pyramidal Cells of Mammalian Neocortex Associated with Increased Use.
Show BibTeX
@article{morphological_changes_in_pyramidal_cells_of_mammalian_neocortex_associated_with__g4427,
  author = {L. T. Rutledge and C. Wright and J. Duncan},
  title = {Morphological Changes in Pyramidal Cells of Mammalian Neocortex Associated with Increased Use},
  year = {1974},
  
  
}
No DOI on file for this study.

Quick Questions About This Study

Yes, cats receiving daily electrical stimulation for several weeks showed significantly more terminal branching, greater lengths and more spines in apical dendrites of cortex contralateral to the stimulated side, which the authors interpret as postsynaptic growth.
The cats received 20 trains (2 sec each) of electrical stimulation to the suprasylvian gyrus daily for several weeks, after which pyramidal neurons in contralateral cortex had more terminal branching and more spines.
Apical dendrites of layers I and II pyramidal cells in cortex contralateral to the stimulated side showed significantly more branchings in terminal regions and greater lengths, with more spines on oblique, vertical, and terminal portions.
The changes appeared in cortex contralateral to the stimulated side, where apical dendrites of layers I and II pyramidal cells had significantly more branchings in terminal regions, greater lengths, and terminated nearer the pia than they did on the stimulated side.
Yes, the study found more spines on oblique, vertical, and terminal portions of apical dendrites, more terminal branching, and a general appearance of increased density of apical dendrites near the pia, interpreted as postsynaptic growth in some cortical neurons.