SLEEP 2011 Abstract Supplement

A. Basic Science V. Physiology
0110
TITLE: SLEEP RESTRICTION IN RATS UPREGULATES
THE EXPRESSION OF STRIATAL OPIOID PEPTIDE GENES
INVOLVED IN FOOD REWARD: COMPARISON TO EFFECTS
ON FEEDING-RELATED HYPOTHALAMIC PEPTIDE GENES
Baldo B, Hanlon E, Jones S, Paletz E, Bremmer Q, Benca R
Psychiatry, University of Wisconsin-Madison, Madison, WI, USA
Introduction: Chronic sleep restriction (SR) in rodents markedly upregulates
daily food intake and produces weight loss; the neural mechanisms
underlying these effects are unknown. We aimed to compare the
effects of SR on the expression of striatal opioid peptide genes, thought
to regulate reward-driven, “non-homeostatic” feeding, to effects on
the expression of the hypothalamic peptides NPY, POMC, HCRT, and
MCH. These peptides are thought to be involved in “homeostatic” feeding,
and, in the case of HCRT, arousal.
Methods: Male Sprague-Dawley rats were subjected to 70% SR using
the Conveyer-Over-Water (COW) apparatus, in which behavioral state
is inferred from motion detection and a conveyer belt triggered when the
animal falls asleep. The following control groups were used: unmanipulated
home cage controls, food-deprived controls, and apparatus controls
kept in the COWs but receiving conveyer belt motion only when
awake. After chronic SR, rats were sacrificed, trunk blood obtained for
the analysis of insulin, leptin, and ghrelin, and brains harvested for in
situ hybridization.
Results: Sleep restriction markedly upregulated striatal enkephalin
mRNA; none of the control groups showed this effect. NPY expression
in the hypothalamic arcuate nucleus was upregulated in both the sleepand
food-deprived groups. Analysis of POMC, HCRT, and MCH gene
expression is ongoing. Finally, sleep restriction suppressed plasma insulin
and leptin.
Conclusion: SR markedly upregulated striatal expression of enkephalin,
which mediates binge-like feeding especially upon palatable foods.
In contrast, hypothalamic NPY was affected by both sleep- and foodrestriction.
Possibly, hypothalamic changes reflect weight loss-induced
alterations in circulating hormones (particularly leptin). The striatal
changes, on the other hand, may result from paracrine factors directly
related to sleep homeostasis. The present findings reveal a novel neural
pathway through which sleep deprivation may affect changes not only
in food reward, but also drug-seeking, reward learning, and other motivational
functions mediated by the striatum.
Support (If Any): This work was supported by research grant R01
HL86465, from the National Institutes of Health.
0111
CHANGES IN INSULIN SECRETION AND SENSITIVITY
RELATED TO HABITUAL SLEEP CURTAILMENT IN YOUNG
ADULTS WITH PARENTAL HISTORY OF TYPE-2 DIABETES
Booth JN 1 , Darukhanavala A 1 , Bromley L 1 , Whitmore H 1 , Imperial J 2 ,
Penev P 1
1
Section of Endocrinology, University of Chicago, Chicago, IL, USA,
2
General Clinical Research Center, University of Chicago, Chicago, IL,
USA
Introduction: Short sleep is associated with increased risk of type-2
diabetes, possibly related to chronic changes in insulin secretion and action.
We examined whether habitual sleep curtailment is accompanied
by alterations in insulin resistance and pancreatic beta-cell function in
healthy young adults with increased risk of type-2 diabetes due to positive
parental history for the disease.
Methods: Thirty one (19F/12M) consecutively enrolled non-obese
participants with parental history of type-2 diabetes (mean [SD] age
26 [4] y, BMI 24 [2] kg/m2) completed a 75-g oral glucose tolerance
test, overnight laboratory polysomnography, and 2 weeks of home sleep
and physical activity monitoring by wrist and waist actigraphy. We used
analysis of covariance (SPSS 17.0) to compare OGTT-based indices of
glucose tolerance, beta-cell function and insulin resistance, while controlling
for differences in everyday physical activity between usual (average
sleep time 377 min/day; range 358-461; N=17) and short sleepers
(average sleep 305 min/day; range 231-342; N=14).
Results: Both sleep groups were matched by age, gender and BMI, and
had similar quantity and quality of sleep during laboratory polysomnography.
Short sleepers had less total daily body movement and time
spent in moderate plus vigorous physical activity (P