Neurobehavioral Plasticity: Learning, Development, and Response to Brain Insults

By Norman E. Spear; Linda P. Spear et al. | Go to book overview

observed with a number of model systems, such as development, LTP, environmental enrichment, NMDA administration, and adult reactive synaptogenesis. Modifications in synaptic structure as outlined in this chapter would markedly alter synaptic physiology, allowing, as Hebb suggested, a more efficacious future transmission across the synapse. This process of synaptic morphological plasticity is presumed to underlie processes such as learning and memory.

As pointed out earlier, the storage of information likely involves interactions within a complex network of synaptic contacts, including a probable balance between different synaptic types, such as excitatory and inhibitory synapses. Therefore, the process outlined in this chapter is, at best, a description of events occurring only in certain synaptic populations within a larger complex system. Such a system could contain synapses undergoing different or opposing processes to those described.

It is also important to realize that synaptic activation may not necessarily proceed through all three phases outlined here, to the final production of complex perforated synapses or new synapses and dendritic material. It would seem reasonable that the extent of the morphological changes would be relative to the degree of synaptic activation. It might be possible, for example, for certain levels of stimulation to induce changes only of Phase I; because these events involve only transient shape changes, the record, either electrophysiologically or behaviorally, would be short-lived. Greater levels of activation may be necessary to induce the changes in Phase II, or ultimately Phase III, which would translate into progressively larger and more permanent morphological changes, and therefore more permanent electrophysiological or behavioral records of the events.

It is tempting to correlate the stages of synaptic efficacy change with the temporal components of memory. For example, immediate or short- term memory might involve the earlier phases of synaptic modification, whereas long-term memory storage would require the more permanent later phases of synaptic structural changes. Alterations in postsynaptic shape could be rapidly produced and short-lived, and as such could form an excellent system for the short-term storage of information. The formation of the very large perforated synapses, new synapses, dendritic spines, and dendritic length would represent a more substantial, less rapidly reversed, investment of cellular resources, forming an ideal basis for the longer term storage of memories.


REFERENCES

Adinolfi A. M. ( 1972a). "Morphogenesis of synaptic junctions in layers I and II of the somatic sensory cortex". Experimental Neurology, 34, 372-383.

Adinolfi A. M. ( 1972b). "The organization of paramembranous densities during postnatal maturation of synaptic junctions in the cerebral cortex". Experimental Neurology, 34, 383-393.

-198-

Notes for this page

Add a new note
If you are trying to select text to create highlights or citations, remember that you must now click or tap on the first word, and then click or tap on the last word.
One moment ...
Default project is now your active project.
Project items

Items saved from this book

This book has been saved
Highlights (0)
Some of your highlights are legacy items.

Highlights saved before July 30, 2012 will not be displayed on their respective source pages.

You can easily re-create the highlights by opening the book page or article, selecting the text, and clicking “Highlight.”

Citations (0)
Some of your citations are legacy items.

Any citation created before July 30, 2012 will labeled as a “Cited page.” New citations will be saved as cited passages, pages or articles.

We also added the ability to view new citations from your projects or the book or article where you created them.

Notes (0)
Bookmarks (0)

You have no saved items from this book

Project items include:
  • Saved book/article
  • Highlights
  • Quotes/citations
  • Notes
  • Bookmarks
Notes
Cite this page

Cited page

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited page

Bookmark this page
Neurobehavioral Plasticity: Learning, Development, and Response to Brain Insults
Table of contents

Table of contents

Settings

Settings

Typeface
Text size Smaller Larger Reset View mode
Search within

Search within this book

Look up

Look up a word

  • Dictionary
  • Thesaurus
Please submit a word or phrase above.
Print this page

Print this page

Why can't I print more than one page at a time?

Full screen
/ 472

matching results for page

Cited passage

Style
Citations are available only to our active members.
Sign up now to cite pages or passages in MLA, APA and Chicago citation styles.

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn, 1992, p. 25).

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences." (Einhorn 25)

"Portraying himself as an honest, ordinary person helped Lincoln identify with his audiences."1

1. Lois J. Einhorn, Abraham Lincoln, the Orator: Penetrating the Lincoln Legend (Westport, CT: Greenwood Press, 1992), 25, http://www.questia.com/read/27419298.

Cited passage

Welcome to the new Questia Reader

The Questia Reader has been updated to provide you with an even better online reading experience.  It is now 100% Responsive, which means you can read our books and articles on any sized device you wish.  All of your favorite tools like notes, highlights, and citations are still here, but the way you select text has been updated to be easier to use, especially on touchscreen devices.  Here's how:

1. Click or tap the first word you want to select.
2. Click or tap the last word you want to select.

OK, got it!

Thanks for trying Questia!

Please continue trying out our research tools, but please note, full functionality is available only to our active members.

Your work will be lost once you leave this Web page.

For full access in an ad-free environment, sign up now for a FREE, 1-day trial.

Already a member? Log in now.