7 No. 4
of a Lullaby
In Emory's growing sleep
research program, scholars encounter mystery and paradox
breath and life
do have some very good people [in sleep research], and we’re
gaining a critical mass to do this kind of work.
Donald L. Bliwise, Professor of Neurology, Program Director, Sleep,
Aging and Chronobiology
think there are valuable things we can learn about how plastic or
mutable the circadian system is by looking at people who travel
abroad and contend with jet lag, or people from different cultures.
Hillary Rodman, Associate Professor of
Power of Sleep
Exploring disorder and disturbance
P. Parker, Edith F. Honeycutt Professor of Nursing
A Few Drinks Between Friends?
the ancient drinking party with students
Bing, Associate Professor of Classics
and Transformative Knowledge
Practicing what we profess
D. Scheib, Associate Professor of Pastoral Care and Pastoral Theology
Exchange: What’s most important to know about
the relationship between sleep and medicine?
Don Bliwise: There are three cardinal tenets of
sleep medicine. First, diseases don’t disappear when patients
go to sleep. The manifestations of a disease may change, but the
diseases are still there (in some cases they may be worse), and
for many years medicine has ignored that. Second, the treatment
of any particular disease can have greater or lesser benefit depending
on the time of day it is administered. And third, there are some
diseases that are unique to sleep and occur only when a patient
is asleep. These constitute the bulk of clinical practice in most
sleep disorders centers.
AE: How do aging and sleep interact?
DB: There are predictable changes in the body clock
with age. The timing of the minimum of the body temperature cycle
is related to the age of a person, such that minimum temperature
occurs earlier (relative to clock time) in an older person than
in a younger one. That explains a lot about the chronobiologic changes
we see as a function of age. For example, why do college students
stay up until four in the morning? Yes, they’re socializing,
but their biologic clock predisposes them to have a very delayed
minimum body temperature nadir, and they don’t get sleepy
until late into the night. By contrast, an older person’s
body temperature minimum occurs much earlier in their twenty-four-hour
day, and that compels them to go to bed earlier in the evening,
wake up too early in the morning, and be unable to get back to sleep.
AE: How does Emory fit into the broader picture
of sleep research?
DB: Emory has come a little late into the game.
The University of Chicago and Stanford have long-standing histories
in sleep research. rem sleep was discovered at the University of
Chicago in 1953. Stanford pioneered the development of sleep disorders
medicine as a subfield. There’s been phenomenal growth in
clinical sleep disorders medicine. Most major hospitals have a sleep
disorders laboratory associated with them. It would be no different
than having a pulmonary or electrocardiology lab.
We have unique situation: a four-bed lab dedicated only for research
and a four-bed clinical lab for sleep disorders clinic patients.
But even our eight beds combined is much smaller than other academic
medical centers, and I would like to see that expand to sixteen
or twenty beds to put us on par with other major academic medical
centers like Pennsylvania, Harvard, and Stanford. We do have some
very good people, and we’re gaining a critical mass to do
this kind of work. There are so many potential avenues of research:
basic science, animal and human models of disease, basic descriptive
human research on sleep in normal subjects ranging from infants
to children, adults, and geriatrics, even dementia. Intervention
studies and clinical trials are also essential. We have people at
Emory working in many of those areas. It’s just a smaller
group than at some of the other academic centers.
AE: Do we know why we sleep?
DB: The definitive function and purpose of sleep
remain uncertain. There are many clues, and they are all derive
from different kinds of research. If you go down each experimental
path, certain clues emerge. For example, sleep deprivation studies
show that immune function may be compromised during long periods
of sleep deprivation, implying that one of the functions of sleep
is to preserve immune function. But it’s not as simple as
that, because you can miss a night of sleep and not come down with
the flu the next day.
line of research looks at sleep loss and the ability to regulate
glucose. You can’t regulate glucose—which is the fundamental
source of energy for the body—as well if you’re sleep
deprived. Yet another line of research shows that if you deprive
animals of sleep, their ability to regulate their body temperature
decreases. After prolonged periods of time, the predominant effect
of that kind of severe kind of sleep loss is to produce a hypermetabolic
state, and the animal eats huge amounts of food but still cannot
regulate its temperature. That implies that sleep loss is critical
to regulation of body temperature. Also, when animals are then allowed
to have recovery sleep and then given a choice of temperatures in
which to sleep, they tend to choose warmer environments in direct
proportion to the extent of their sleep loss. Sleep seems to be
involved integrally in all of those processes, as well as many others,
such as memory, learning, and mood. But exactly what constitutes
the processes by which sleep routinely helps us maintain homeostasis
and recover those many functions remains tantalizingly elusive.