Page 4-Sunday, October 23, 1977-The Michigan Daily
The Michigan Daily-Sundc
Monkey business it isn't,
but
'
scientists hope prmate researc
yields clues to a distant kin
man
By George Lobsenz
H IS ARM MUSCLES TENSE as he places
his hand on a metal knob attached to an
extension of his chair. As he turns the
knob, a soft cooing noise intones from one of four
loud-speakers arrayed in a semi-circle about five
feet in front of him. Fidgety and seemingly im-
patient a few moments ago, he now sits frozen, his
eyes fixed in a daze of concentration. He strains
perceptibly, listening for the cooing to pass
fleetingly from the first speaker to one of the other
three and back again. Abruptly, he breaks his grip
on the knob, indicating that he's heard the sound
switch speakers, and he immediately plunges his
hand into an adjacent bowl. If his sense of hearing
has served him well and he has indeed caught the
subtle shift, he'll find what he's looking for in the
George Lobsenz is a Daily managing editor.
bowl: his hard-earned delicacy-a banana
flavored pellet.
For Oscar, such routines are all part of his job
as a laboratory monkey at the Primate
Laboratory of the University's Kresge Hearing
Research Institute. A small, sandy-brown Rhesus,
Oscar plays an impottant role in an experiment
into how primates locate sources of sound. Yet, he
is just one in a troupe of specially-trained
monkeys used by the University in tests ranging
from drug effectiveness to plastic surgery.
Through such data collected on Oscar and his
friends, researchers at the University hope to
derive some theories pertinent to a distant
relative of Oscar's-man.
* By using the primate as a stand-in for humans,
researchers here are pursuing some 20 different
studies bound to shed light on the physiological
laboratories via three different routes. According
to Beecher, "You can get them from laboratory
animal suppliers, you can get them from the
various breeding colonies around the country or
you get them from other laboratories, either by
trading animals or buying them outright."
Once at the Institute, the monkeys settle into a
mundane, tedious sort of laboratory life. Usually,
the monkeys are assigned to one project for a long.
stretch. They typically work and eat at set hours.
The Institute fare features "standard laboratory
Chow," says Beecher-"Purina Monkey Chow,"
but they get special treats much of the time.
"They get a fruit supplement, usually orange
juice," says Beecher, "but I don't think it gives
them anything nutritionally that they don't get
from the Chow. I think the supplement is just for
their entertainment-they really like it."
In the bowels of the Medical Science II building,
monkeys are injesting substances far different
from .the innocuous laboratory foods. These
monkeys are taking part in a pharmacological
inquiry dating back to the 1940s.
Scientists here are searching for a painkiller
that is neither physically nor psychologically ad-
dictive. Their probe is designed to weed out the
drug compounds that, while effective as pain-
killers, create dubious physical and/or
psychological dependencies.
Monkeys, therefore, are each given six injec-
tions of morphine to produce a state of physical
drug dependency. After the sixth injection, the
monkeys are left to lapse into withdrawal. They
are then given a dose of the drug compound in
question. The effect of this -second drug is
monitored to see if it reverses the withdrawal
symptoms brought on by the morphine. If the drug
succeeds in pacifying the monkey in the pangs of
withdrawal, researchers await the new with-,
drawal symptoms from the replacement drug. If
this does occur, that drug has failed the test,
another drug is administered, monitored, and the
cycle begins anew.
However, researchers are waiting for the drug
that will arrest withdrawal without inciting
another, and according to Dr. James Wood, a
pharmacologist involved in the study, when such a
novel drug is found,-it will be scrutinized for its
chemical properties.
N A COMPLEMENTARY STUDY, 24 monkeys
are used to test the "attractiveness" of certain
drugs. The experiment's objective, Woods ex-
plains, is to determine what compounds monkeys
formed promptly enough, the monkey gets a shot
of the experimental drug through a tube that en-
ters a vein located in his back.
Several factors reflect how well the monkey
likes any particular drug. The number of times the
monkey pushes the lever is one indicator. The
monkey will presumably push the lever more
times for a drug he prefers than for one to which
he is indifferent. Also significant is the reaction
time. Persistence of response over the course of
several trials also indicates preference.
All of this data is recorded on a computer to
facilitate comparisons between particular drug
compounds.
Woods says he believes the data from these tests
and other related research will make it possible,
four or five years from now, to identify painkillers
that act without addictive or harmful side effects.
One line of primate study pursued vigorously at
the University lies in the area of primate com-
munication and the role played by hearing. The
"sound localization" experiment involving Oscar
is one of several experiments being performed
under the general direction of Drs. William Steb-
bins and David Moody at the Kresge Institute.
T HIS EXPERIMENT IS designed to deter-
mine how accurately primates can locate
sound sources. In the lab set-up, Oscar can
and, to some extent, psychological processes of
man.
Among them, dental researchers are examining
the effects of aging on the bones and muscles of
the head and face, while also experimenting with
tooth transplantation. Endocrinologists are
studying-the sequence of events which lead to the
onset of puberty. Neurologists are exploring the
various central nervous system mechanisms in-
volved in pain sensation.
The practical human benefits that may result-
from primate research have been amply demon-
strated in the past. Experiments with Rhesus
monkeys led to the discovery of crucial Rh fac-
tor in red blood cells, named for the species.
Primates were employed to test the effects of
weightlessness and extreme gravitational forces
upon take-off and re-entry into the at-
mosphere--investigations which paved the way
for Alan Shepard's pioneer orbit of the earth. And
just earlier this month, coronary specialist Dr.
Christian Barnard equipped an ailing man's heart
with a back-up-or piggy-back-heart from
a chimpanzee. Although the recipient died several
PHOTOS BY ANDY FREEBERG
days after the operation, other attempts to im-
plant primate organs have been more successful.
One patient survived with a chimpanzee kidney
for eight months. Such advances indicate primate
organs can one day serve as human life-saving
devices.
TOSERVE SUCH RESEARCH, _laboratory>
primates like Oscar usually start their
careers at an early age when they can still
adapt easily to the laboratory routine.
"We try to get them while they'rc still young so
that they're more tractable," says Mike Beecher,
research associate at the Kresge Institute. "We
usually get them when they're, you might say,
teenagers." ,
These "teenagers" arrive at University
prefer-a possible measure of how
psychologically addictive a certain drug might be.
Naturally, scientists are most interested in the
compounds monkeys like least.
Woods likens the role of a monkey in this study
to that of a "taste-tester in a winery." The
monkeys have the opportunity to sample a variety
of substances and then indicate their preferences.
The experimental set-up is such that the monkey
administers the drug to himself at whim. In order
to get a dose, the animal must follow a learned
behavioral routine which centers around a box
with levers. During a test session, a light on the
box goes on at ten-minute intervals indicating the
monkey can try for a dose. The.trial requires the
monkey to press a. lever beneath the light a
predetermined number of times. Ifthe task is per-
show his proficiency in sound localization by
correctly determining when the cooing sound
shifts from one speaker--or one source-to an-
other.
Post-doctoral fellow Charles Brown, director of
the experiment, says he has discovered monkeys
are sensitive to certain acoustic features which
simplify sound localization. For example, the
more frequencies used in a sound, the easier the
sound is for the monkey to locate.
In future investigations, Brown says he hopes to
determine how accurately the acoustical features
correspond with selected monkey calls where the
"meaning" of each particular call is known. A
warning cry, for instance, will presumably con-
tain acoustical features that make it highly
locatable because it is adaptive for the species.
From these sound location experiments, the
Kresge researchers aim to discover how primate
hearing systems have evolved to complement
communication systems.:
Kresge Institute Researcher Charl
Oscar on the head in the anechoic c
site of sound localization experime
such research, laboratory primates l
ally start their careers at an early
can still adapt easily to the laborat
In a related experiment, several species of
monkeys are tested to see how well they can dif-
ferentiate between two distinct sounds made by,_ .
Japanese macaques (a monkey species). With the
macaque responses to a call from one of their kind "
acting as a control, researchers want to test how
successfully other species can distinguish the two
types of macaque sounds.
The phenomenon is analogous to the human ex-
perience of encountering new types of sounds
while learning a second language. A familiar
example is the inability of the Chinese to
distinguish between the "r" and "1" sounds in
English. Having no such sounds in their own
language, they cannot easily differentiate the two. S, .
Whatever the fruits of primate research, one
might wonder what is the ,ultimate fate of
monkeys permanently damaged in experiments.
One researcher was blunt about it. "If some of ;
their functions are severely impaired, they may
be sacrificed," says Mike Beecher. And for the
normal laboratory monkey? "Very few live to old I
age," Beecher explains. "Most spend the rest of
their lives in laboratories. After all, they don't go
off to old monkey homes."
THIS JAPANESE MACAQUE takes five after doing his daily shift in the sound discrimination experi-
ment at the Kresge Institute. The restraining chair is commonly used in primate laboratories as a means
of transporting the animals.to and from their quarters.