Effect of satiation on brain activity in obese and lean women.
OBJECTIVE
To investigate the response of the brains of women to the ingestion of a meal.


METHODS
We used measures of regional cerebral blood flow (rCBF), a marker of neuronal activity, by positron emission tomography to describe the functional anatomy of satiation, i.e., the response to a liquid meal in the context of extreme hunger (36-hour fast) in 10 lean (BMI < or = 25 kg/m(2); 32 +/- 10 years old, 61 +/- 7 kg; mean +/- SD) and 12 obese (BMI > or = 35 kg/m(2); 30 +/- 7 years old, 110 +/- 14 kg) women.


RESULTS
In lean and obese women, satiation produced significant increases in rCBF in the vicinity of the prefrontal cortex (p < 0.005). Satiation also produced significant decreases in rCBF in several regions including the thalamus, insular cortex, parahippocampal gyrus, temporal cortex, and cerebellum (in lean and obese women), and hypothalamus, cingulate, nucleus accumbens, and amygdala (in obese women only; all p < 0.005). Compared with lean women, obese women had significantly greater increases in rCBF in the ventral prefrontal cortex and had significantly greater decreases in the paralimbic areas and in areas of the frontal and temporal cortex.


CONCLUSIONS
This study indicates that satiation elicits differential brain responses in obese and lean women. It also lends additional support to the hypothesis that the paralimbic areas participate in a central orexigenic network modulated by the prefrontal cortex through feedback loops.
Gautier
J F
JF
Clinical Diabetes and Nutrition Section, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Phoenix, Arizona 85016, USA.
Del Parigi
A
A
Chen
K
K
Salbe
A D
AD
Bandy
D
D
Pratley
R E
RE
Ravussin
E
E
Reiman
E M
EM
Tataranni
P A
PA
D000328:Adult; D015992:Body Mass Index; D001921:Brain / Q000098:blood supply* / Q000502:physiology*; D002421:Caudate Nucleus / Q000098:blood supply; D005230:Fatty Acids, Nonesterified / Q000097:blood; D005260:Female; D005502:Food; D005625:Frontal Lobe / Q000098:blood supply; D006624:Hippocampus / Q000098:blood supply; D006801:Humans; D007328:Insulin / Q000097:blood; D020738:Leptin / Q000032:analysis; D008032:Limbic System / Q000098:blood supply; D009765:Obesity / Q000473:pathology*; D017397:Prefrontal Cortex / Q000098:blood supply; D012527:Satiation / Q000502:physiology*; D013702:Temporal Lobe / Q000098:blood supply
D005230:Fatty Acids, Nonesterified; D007328:Insulin; D020738:Leptin