Table Of ContentHibernation
and the
Hypothalamus
Neuroscience Series
EDITOR:
Arnold Towe, University of Washington
PREVIOUS TITLES:
Physiological Basis of the Alpha Rhythm
by Per Andersen (University of Oslo) and
Sven Andersson (University of Gothenburg)
The Bisected Brain
by Michael S. Gazzaniga (New York University)
Hibernation
and the
Hypothalamus
NICHOLAS MROSOVSKY
DEPARTMENTS OF ZOOLOGY AND PSYCHOLOGY
UNIVERSITY OF TORONTO
ApPLETON -CENTURY- CROFTS
EDUCATIONAL DIVISION
MEREDITH CORPORATION
Copyright © 1971 by MEREDITH CORPORATION
Softcover reprint of the hardcover ISt edition 1971
Al! rights reserved. This book, or parts thereof,
must not be used or reproduced in any manner
without written permission. For information address
the publisher, Appleton.Century-Crofts, EducationaI
Division, Meredith Corporation, 440 Park Avenue
South, New York, New York 10016.
721-1
Library of Congress Catalog Card Number: 71-120859
ISBN 978-1-4684-7178-6 ISBN 978-1-4684-7176-2 (eBook)
DOI 10.1007/978-1-4684-7176-2
39°-65365-9
Preface
Mammalian hibernation is commonly thought of as something completely
out of the ordinary, a "unique and unorthodox state." The present book takes
the opposite view. It argues that the physiological achievements of hibernators
do not deEend on special mechanisms but on special use of ordinary mechanisms.
It is precisely this that makes the hibernators important. If the hibernators de
pend on some unique physiological principle their study is that of a biological
curio. But if they are using basic mammalian systems in a quantitatively extreme
way, then they are a naturally occurring preparation of enormous potential.
Hibernation involves every aspect of the animal's biology from fat metabo
lism to behavior, from thermoregulation to dental caries; every system in the
body is affected in some way or other by hibernation. A comprehensive account
of hibernation would be almost coextensive with an account of the whole of
mammalian biology. The present book does not attempt to describe everything
that has been discovered about hibernation. Excellent coverage for that already
exists in the proceedings of three recent symposia and in the other major source
materials listed on page 233. There is in fact an enormous amount of information
already available. But there is a difference between information and understanding.
Despite the increasing volume of research and growing interest in mammalian
hibernation, there is little appreciation of the essential characteristics of the
phenomena. The pieces of the puzzle lie scattered.
The present book concentrates on one aspect of hibernation phenomena,
the nature and role of central nervous system regulating mechanisms, and attempts
to make some coherence out of the facts. As such it is not so much concerned with
listing facts as with their interpretation and their relation to mammalian regulation
in general. In a number of places I have disagreed with the conclusions and
emphases others have placed on their own results. I come from a tradition where
disagreement with interpretation of results has no implication about the intelli.
gence or worth of an endeavor. It implies only disagreement with interpretation
and as such can be a valuable part of the process of sharpening and formulating
issues. Indeed, I feel greatly indebted to many people, both in hibernation reo
search and outside it, for criticism, ideas, information, and stimulation.
v
It is not possible here to thank everyone who helped me in some way or
other; this endeavor has taken place in a matrix of many other people's goodwill
and cooperation and I am most grateful to them. However, I should like to
mention Dr. R. V. Short in whose drawing room as a student I first saw an
animal in hibernation, a hedgehog brought in from outside to demonstrate
J.
arousal. I am especially happy to thank Dr. Sara Shettleworth for many con
structive suggestions and discussions, and Dr. Ursula Rowlatt for her valuable
and sparkling criticisms. Dr. C. P. Lyman and Dr. E. M. Striker kindly com
mented on the manuscript. Any errors or misconceptions still remaining are my
own responsibility. I am grateful to my colleagues for advice on numerous
points and should particularly like to thank Dr. Glenn Macdonald for en
couragement. The late Dr. K. C. Fisher gave me generous support. Grants from
the National Research Council of Canada and their approach to financing ex
perimental work have been much appreciated, and the operation of the Hiberna
tion Information Exchange by Dr. Albert Dawe and his staff has been invaluable
(see Dawe, 1961). I thank Mrs. Regina Niedra for her patience with the figures
and Miss Eileen Asome, Mrs. Kirsteen Lang, Mrs. Anna Dart, Mr. Hugh Craske,
Miss Rosemary Crean, Mr. Norman Hatton, Mrs. Janice Sperry, Mr. and Mrs.
K. Ponomarev, Miss M. Karlsons, and Miss Janet Baher for help with materials
and the preparation of the manuscript.
For permission to use illustrations and material (acknowledged in detail on
the appropriate page) I thank: J. R. Alcorn, R. K. Andjus, E. D. Bailey, H. Balin
ska, G. A. Bartholomew, J. Benoit, T. J. Cade, B. Canguilhem, J. J. Christian,
J. D. Corbit, M. Critchley, S. A. D'Angelo, D. E. Davis, D. S. Farner, C. L.
Hamilton, H. T. Hammel, G. W. Harris, A. M. Hoffman, R. A. Hoffman, E. C.
c.
Jaeger, E. W. Jameson, Kayser, G. C. Kennedy, M. Khai'ry, R. Kristoffersson,
R. E. MacMillen, J. F. Manery, W. V. Mayer, R. K. Meyer, S. McKeever, N. E.
Miller, P. R. Morrison, R. E. Nisbett, E. T. Pengelley, V. D. Ramirez, C. P.
Richter, W. W. Roberts, S. S. Schachter, J. H. Smit-Vis, D. Snow, F. Strumwas
ser, P. Teitelbaum, D. W. Thomas, P. Q. Tomich, J. W. Twente, O. Wade,
L. J. Wells, and the American Association for the Advancement of Science,
American Medical Association, American Ornithologists Union, American Physio
logical Society, American Psychological Association, American Society of Mam
malogists, Bailliere, Tindall and Cassell Ltd., British Ornithologists' Union,
Cambridge University Press, Carnegie Institution of Washington, Centre National
de la Recherche Scientifique, Duke University Press, Experientia, Federation of
American Societies for Experimental Biology, W. H. Freeman and Company,
Finnish Academy of Science and Letters, Johns Hopkins Press, Journal of Phys
iology, J. B. Lippincott Company, MacMillan (Journals) Ltd., The Marine
Biological Laboratory, Woods Hole; Masson et Cie, Museum of Comparative
Zoology, Harvard College; National Research Council of Canada, Oliver and
Boyd Ltd., The Ottawa Field-Naturalists' Club, Panstwowe Wydawnictwo Na
ukowe, Pergamon Publishing Company, Periodica, The Society of the Sigma XI,
University of California Press, The University of Chicago Press, University of
Illinois Press, The U.S. National Academy of Sciences, The Wistar Institute of
Anatomy and Biology.
VI
Contents
Preface / v
Frontispiece / viii
1. FUNCTIONAL AND PHYLOGENETIC PERSPECTIVE / I
2. HIBERNATION AND THE HYPOTHALAMUS / 20
3. THE MEDIAL HYPOTHALAMUS AND PRE HIBERNATION OBESITY:
A THEORY BASED ON BEHAVIORAL TESTS / 25
4. CONTROL SYSTEMS FOR ANNUAL CYCLES / 103
5. THERMOREGULATION DURING HIBERNATION:
THE ADJUSTABLE THERMOSTAT / 147
6. THE CONDITIONS FOR TORPOR / 168
7. HYPOTHALAMIC PLASTICITY / 208
8. IMPLICATIONS AND SPECULATIONS / 215
Bibliography / 233
MAIN SOURCES FOR REFERENCES ON HIBERNATION / 233
REFERENCES / 233
ADDITIONAL REFERENCES / 270
Index / 273
FRONTISPIECE. An obese dormouse, Glis glis. The animal, a female,
was kept in a warm laboratory, 25+4°C, on a diet of sunflower seeds,
apple, and a standard rodent food. Dormice are somewhat smaller than
laboratory rats. The length of this species, excluding the tail, is about 15
cm. When photographed the animal weighed 280 g. Subsequently it put
on more than 200 additional grams, reaching a weight of 494 g. (Photo
graph by E. Hitchcock. From Mrosovsky. 1968. Scientific American, 218
( 3 ) : 114. Copyright 1968 by Scientific American, Inc. All rights reserved.)
Hibernation
and the
Hypothalamus
1
Functional and Phylogenetic Perspective
Functional definition-hibernation and migration
Hibernation is a solution to the problem of seasonal food short
age. Essentially, it is a physiological solution. Although behavior such as
preparation of the nest and provision of the burrow with food may be
important, the lowering of metabolic energy expenditure is central to
hibernation. In contrast migration, although accompanied by physiological
changes such as premigratory fattening and endocrine involution, is
essentially a behavioral solution,a moving of the whole animal to the
abundance of other habitats. Hibernation is physiological acceptance of re
duced energy sources: migration is behavioral defiance of local conditions.
Although hibernation is the more remarkable of these two great
biological solutions to the threat of seasonal scarcity, it is migration that
stands in the spotlight of scientific and public imagination. There are two
main reasons for this, and both are ill-founded. First, there is the
tendency to regard a behavioral response as in some sense superior to a
physiological response. Second, there is the idea that while hibernation is
based on a primitive physiology, migration is a quite exceptional and
special example of behavior.
But as behavior, migration is no more remarkable than courting and
mating or other response sequences. This is not to belittle migration. It
is an intricate and valid achievement and seems to depend, in some cases,
I
