Models and Analogues in Biology

By Society for Experimental Biology | Go to book overview

COMPUTERS AND THE NERVOUS SYSTEM

By W. K. TAYLOR

Department of Anatomy, University College, London


INTRODUCTION

The value of predictions made about the behaviour of the nervous system by models and analogues depends strongly on the accuracy of the assumptions concerning neuron properties on which their design is based. The most accurate assumptions that have been made for the properties of a particular neuron membrane are those of Hodgkin & Huxley ( 1952). These were based on careful measurement and led to equations for the membrane potential which were only solved after considerable labour. Extended solutions were obtained by Cole ( 1955) who used a high-speed digital computer. Minutes of computer time were required to predict msec. of membrane potential and as a digital computer can only handle one computation at any instant of time, a whole set of computers would be required for simultaneous calculation of the interactions between a set of nerve membranes. The alternative would be to compute each membrane potential in turn but the length and complexity of a programme based on the original equations would be prohibitive for two or more interacting membrane models.

Lack of quantitative physiological data has held up the extension of digital computer techniques to neural interaction problems and in particular to the mechanism of synaptic transmission that plays such an important part in the functioning of the nervous system. It is understandable, therefore, that there have been many suggestions for approximating the description of neural activity so that larger numbers of neurons can be considered simultaneously. Some approximations have led to the construction of electrical models but the value of their predictions is often difficult to assess.

Uttley ( 1954) follows a suggestion made by Eccles ( 1953) and assumes that a neuron fires if the post-synaptic potential rises by ten, or in general, n times the rise produced by a single synaptic impulse. This is probably quite correct for the single afferent volley to a motoneurone considered by Eccles but it does not tell us what firing-rate to expect if impulses continue to arrive and produce temporal summation. Temporal summation plays an important part in neurons like Renshaw cells that have post-synaptic potentials lasting up to 50 msec. or more. McIntyre ( 1956) has pointed out that many other neurons have a much longer lasting post-synaptic potential than the 4 msec. decay time constant of the motoneuron. We thus require, a different model for each neuron type or the same general model with suitably adjusted parameters. Several years ago, the author ( Taylor, 1955) constructed an approximate

-152-

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.
Buy instant access to cite pages or passages in MLA, APA and Chicago citation styles.

(Einhorn, 1992, p. 25)

(Einhorn 25)

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
Models and Analogues in Biology
Table of contents

Table of contents

  • Title Page iii
  • Contents v
  • Preface vii
  • Quantum Physics and Biology† 1
  • Models in Genetics 6
  • Kinetic Models of Development And Heredity 13
  • Tissues in Culture and in the Body 28
  • References 40
  • Models of Muscle 41
  • References 66
  • Mechanical Models in Zoology 69
  • Conclusions 82
  • Physical Models in Biology 83
  • Estimation of Values Of Parameters of a Model to Conform With Observations 102
  • Summary 120
  • Applications of Theoretical Models to the Study of Flight- Behaviour in Locusts and Birds 122
  • References 138
  • Electrical Analogues in Biology 140
  • Computers and the Nervous System 152
  • References 168
  • Models in Cybernetics 169
  • References 190
  • Modelling of Large-Scale Nervous Activity 192
  • Conclusions 197
  • Energy Models of Motivation 199
  • Summary 212
  • The Use of Models in the Teaching Of Embryology 214
  • School Biology as An Educational Model 230
  • Conclusion 241
  • The Problem of Communication In Biological Teaching 243
  • Acknowledge Ments 248
  • A Review of the Symposium: Models and Analogues in Biology 250
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?

Help
Full screen
/ 255

matching results for page

    Questia reader help

    How to highlight and cite specific passages

    1. Click or tap the first word you want to select.
    2. Click or tap the last word you want to select, and you’ll see everything in between get selected.
    3. You’ll then get a menu of options like creating a highlight or a citation from that passage of text.

    OK, got it!

    Cited passage

    Style
    Citations are available only to our active members.
    Buy instant access 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

    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.

    Buy instant access to save your work.

    Already a member? Log in now.

    Oops!

    An unknown error has occurred. Please click the button below to reload the page. If the problem persists, please try again in a little while.