The Limbic System

336 Pages·1982·7.56 MB·English

by  Robert L. Isaacson (auth.)

The Limbic System
SECOND EDITION
The Limbic System
SECOND EDITION
Robert L. Isaacson
State University of New York at Binghamton
Binghamton, New York
Springer Science+Business Media, LLC
Library of Congress Cataloging in Publication Data
Isacson, Robert Lee, 1928-
The limbic system.
Bibliography: p.
Includes index.
1. Limbic system. I. Title. [DNLM: 1. Limbic system. WL 307 I73L]
QP383.2.1821982 599.01'88 82-9077
ISBN 978-1-4757-6757-5 ISBN 978-1-4757-6755-1 (eBook) AACR2
DOI 10.1007/978-1-4757-6755-1
© 1982 Springer Science+Business Media New York
Originally published by Plenum Press, New York in 1982
Sofleover reprint of the hardcover 2nd edition 1982
All rights reserved
No part of this book may be reproduced, stored in a retrieval system, or transmitted
in any form or by any means, electronic, mechanical, photocopying, microfilming,
recording, or otherwise, without written permission from the Publisher
Preface to Second Edition
Like the first edition of The Limbic System, this book was written as
an introduction to the neurobehavioral study of the limbic system; it
is intended for students of brain-behavior relationships in psycho
biology, neurosciences, physiology, and anatomy, as well as those
with clinical interests in the brain and its actions. Also, like the first
edition, the book is flavored with my own orientation to the field
based on some 22 years of active research.
My own perspective on the limbic system is described in the final
chapter. It is an overview of how the different portions of the brain
may work in concert to produce mental and behavioral actions. I do
not hold to the ideas presented there with strong commitment. This
chapter is only an overview and I am sure that other and better
comprehensive approaches will be generated. Nevertheless, it helps
to have some perspective to integrate diverse facts and information.
In regard to other biases, I still believe that the greatest gains in
understanding brain organization will come from studies using the
rat, the cat, and the rabbit. Research using nonhuman primates takes
even more time and expense now than it did in 1974, and the gen
eration of useful information with such species must therefore pro
ceed slowly. Research using humans which is directed toward un
derstanding brain function must depend on examination of the effects
of disease or accidents. Because of this limitation, the study of indi
viduals with similar damage can occur only rarely-if at all. Further
more, as emphasized throughout this edition, the observable con
sequences of brain damage depend on genetic endowment, pre- and
postdamage experiences, and other factors, as well as on the nature
v
vi Preface to Second Edition
of the damage. Therefore, I doubt that much fundamental knowledge
of brain damage will come from studies with the human. As I men
tioned in the preface to the first edition, I am convinced that the use
of the lesion technique will provide the mainstay of future research,
although the goals and methods of lesion studies will be different in
the next 10 to 20 years. Despite its difficulties, which are really similar
to those using brain stimulation or other approaches,l there is no
other method that offers a better way to determine just how large
portions of the central nervous system interact with each other. In
the future such studies will use new neurochemical techniques that
offer the promise of distinguishing cellular from axonal damage and
more biochemical and pharmacological methods to determine the le
sion-induced effects.
In 1974 I admitted that the book could not be considered com
prehensive. Only some 500 references were cited at that time, and it
was clear that many more could have been included. I tried to con
centrate on the ones that seemed most important for current research
and theory. In this second edition there are almost 1,400 references
and, once again, I am sure that they are not comprehensive. The large
increase in the number of references that needed to be noted is a sign
of the scientific information explosion in general and an increased
interest in limbic system structure and function.
In the original preface I expressed my appreciation to the graduate
students who were then in the laboratory. Their thoughts, ideas, and
energies about our research were always exciting. Now, another group
of students is in the laboratory, helping to unravel the secrets of the
brain and behavior. These are John Hannigan, Jr., Joe E. Springer,
and Jeanne Ryan. Daniel K. Reinstein, now at the Massachusetts
Institute of Technology, was with me for most of the period I was
rewriting the book and has helped shape my ideas about the limbic
system. To them, my thanks. They keep me young, at least in spirit.
In the last year or so, I have also had the benefits of collaboration of
two more senior associates, David Hertzler (SUNY-Oswego) and Alex
Poplawsky (Bloomsburg State College), who visited the laboratory for
extended periods.
1 Isaacson, R. L. Brain stimulation effects related to those of lesions. In M. M. Patterson
& R. P. Kesner (Eds.), Electrical stimulation research techniques. New York: Academic
Press, 1981, pp. 205-220.
Preface to Second Edition vii
When starting this second edition, I wrote to several friends who
are recognized authorities in different areas of limbic system research
to solicit their ideas about what should be emphasized. They all re
sponded with their ideas and I have tried to follow their suggestions.
However, it has taken so long to finish this second edition that I am
sure they would make additional or different suggestions now if asked.
I appreciate their help in orienting me to their perspectives. Those to
whom I wrote originally were Graham Goddard, Sebastian P. Gross
man, and Gary W. Van Hoesen. While writing the book I benefited
from discussions of the content and ideas with a number of people,
especially Peter Donovick, Linda Spear, Paul MacLean, Per Andersen,
Larry Swanson, Daniel P. Kimble, and Gyorgy Buzsaki. It may be
hard to recognize the specific contributions made by any of these
people to the book itself but they produced strong influences on my
thinking and my writing.
No book can be prepared without excellent secretarial assistance.
In the first edition it was Mrs. Virginia Walker, at the University of
Florida, who was indispensable. This time it was Mrs. JoAnn Kovalich
at SUNY-Binghamton. Without her help, the book would not have
been finished. Thanks.
ROBERT L. ISAACSON
Binghamton, New York
Preface to First Edition
While this book is intended to be an introduction to the neuroanatomy
of the limbic system and to studies of the behavior of animals in which
the limbic system is stimulated or damaged, it is primarily intended
for advanced students of brain-behavior relationships. I have as
sumed the reader to have some understanding of the structure of the
brain, of basic neurophysiology, and of modern behavioral tech
niques. It has been written for students in graduate programs in
psychobiology, physiological psychology, and the neurosciences, but
it also should be of interest to some medical students and to others
with catholic interests in the biology of behavior.
In the first chapter, I review the structure of the limbic system
and in subsequent chapters consider the behavioral effects of lesions
and stimulation of components of the limbic system. Supplemental
information derived from recording the electrical signals of the brain
is included where it seems appropriate. The final chapter presents a
perspective of the limbic system related to brain stem mechanisms
and the neocortex. Understanding the behavioral contributions of the
limbic system presupposes understanding how the limbic system in
teracts with other systems of the brain.
Even though there is only one chapter overtly devoted to theo
retical issues, various biases of mine influence all chapters. Anyone
reading the book with a critical attitude will soon be aware of them.
I would like to alert the reader to some of them ahead of time.
Simply put: the book is flavored by my own orientation to re
search and reading. For the past 15 years, I have been involved in
research programs which were directed at elucidating the effects of
limbic system destruction on behavior in the rat, cat, and rabbit.
ix
x Preface to First Edition
Therefore, studies using these species and using lesion techniques
probably are overly represented. Other biases of mine will be appar
ent.
In many later chapters, consideration is given to the behavioral
correlates of electrical rhythms recorded from various limbic struc
tures. In these chapters, the effects of electrical stimulation of various
limbic structures on behavior are also discussed. Yet, while these
topics are discussed, much less emphasis is placed on them and on
studies using other species with which I am less well acquainted.
My biases, the topics and areas given emphasis, come in part
from my own research. This research is based on beliefs pertaining
to research strategies. I believe that the most substantial knowledge
available about the limbic system comes from the use of stimulation
and lesion techniques in rats and cats. There is far less useful infor
mation available today arising from work using other techniques and
other species. Since a great deal more information is needed before
an adequate conceptualization can be achieved, this information must
come from careful studies using species like the cat and the rat. These
animals are amenable to laboratory experimentation and can be used
in sufficient numbers so as to provide this information relatively quickly.
If we had to rely on studies using nonhuman primates, our under
standing of the behavioral contributions made by the limbic system
could be greatly delayed. The rat is a necessary laboratory tool, both
for neuroanatomists and for those interested in the behavioral con
tributions of the limbic system. The cat makes its greatest contribution
to neurophysiological research.
The other obvious orientation of the book is the emphasis placed
on understanding the functions of the limbic system as revealed by
destruction of its parts. For 30 years and more, investigations have
been underway of the behavior of animals which have had some
portion of the limbic system destroyed by aspirative or by electrolytic
lesions. Seeking to understand a structure by destroying it is a useful
technique for the behaviorally oriented neuroscientist, although it has
many faults, dangers, and traps for the unwary experimenter. Never
theless, equally dangerous are the faults and traps awaiting those
using other techniques in the neurobehavioral sciences. In reality, the
lesion technique is no better or worse than any other, such as re
cording electrical rhythms or recording from single units. Satisfactory
understanding of the limbic system will not come from the studies
of animals with lesions of this or that part of the limbic system or
Preface to First Edition xi
from the analysis of single cell activity but from theoretical contri
butions derived from the use of all available techniques. Theories
must be evaluated on the basis of whether they make sense of the
facts to be explained. A theory must provide a meaningful and useful
synthesis of information derived from any and all techniques.
Even though the book has a large number of references to pub
lished work on the limbic system, it is not a truly comprehensive
review of the literature. I doubt that a totally comprehensive review
of the experimental literature can be done by anyone. Still, I have
tried to represent fairly most of the important studies which have
influenced present research directions. Nevertheless, some of my col
leagues will be offended by not finding their favorite studies in the
book. To them I apologize for the oversight. On the other hand, some
studies were omitted because I felt that they had not added a great
deal to our understanding of the limbic system. I have tried to select
articles from the literature which highlight information of the greatest
importance for the understanding of the limbic system.
Theories of limbic function have not been emphasized in this
book, since I do not think there are any adequate theories of limbic
system function. My theory, presented in the last chapter, is offered
in an apologetic fashion. At best, it offers only the broadest outlines
for a schema of limbic system function. In almost a playful spirit, it
is offered as a potential stimulant to others. In a lecture given at the
University of Florida in the spring of 1973, Paul MacLean suggested
that scientists did not belong in the laboratory if their work and the
generation of ideas were not fun. All of my days in the laboratory
have been rewarding. I cannot imagine a more fascinating or more
interesting life than struggling to find out how the brain works. There
fore, I hope the reader will evaluate the last chapter with understand
ing.
But my research and study of the limbic system is motivated by
far more than the joy it provides. It is motivated by the belief that
learning at least some of the secrets of the nervous system will be of
value to mankind. This is not an intangible or abstract motive. Re
tarded children are very real, as are people with other brain disorders.
While much of my present work is directed toward problems of gen
eral interest rather than toward retardation specifically, the ultimate
goal is to better understand the human condition and to help provide
information on which effective therapies and treatments for the brain
damaged can be based.