Low dopamine striatal D2 receptors are associated with prefrontal metabolism in obese subjects: Possible contributing factors
Section snippets
Subjects
Ten morbidly obese subjects (5 women and 5 men, mean 35.9 ± 10 years of age) with mean body mass (BMI: weight in kilograms divided by the square of height in meters) of 51 ± 5 kg/m2 were selected from a pool of obese subjects who responded to an advertisement. Twelve non-obese subjects (6 women and 6 men, mean 33.2 ± 8 years of age) with mean BMI of 25 ± 3 kg/m2 were selected for comparison. Participants were screened carefully with a detailed medical history, physical and neurological examination,
Results
The measures of striatal D2 receptor availability (Bmax/Kd) were significantly lower in the obese subjects than in the non-obese controls (2.72 ± 0.5 versus 3.14 ± 0.40, Student t test = 2.2, P < 0.05).
The SPM analysis done on the obese subjects to assess the correlation between D2 receptor availability and regional brain glucose metabolism showed it was significant in 4 clusters that were centered in (1) left and right prefrontal (BA 9), CG (BA 32) and left lateral orbitofrontal cortices (BA 45): (2)
Discussion
Here we show that in morbidly obese subjects DA D2 receptor availability was associated with metabolic activity in prefrontal regions (DLPFC, medial orbitofrontal cortex and anterior CG). These regions have all been implicated in regulating food consumption and in the hyperphagia of obese individuals (Tataranni et al., 1999, Tataranni and DelParigi, 2003). We also show a significant correlation with metabolism in somatosensory cortex (postcentral cortices) that was significant both in obese and
Acknowledgments
We thank David Schlyer, David Alexoff, Paul Vaska, Colleen Shea, Youwen Xu, Pauline Carter, Karen Apelskog, and Linda Thomas for their contributions. This research was supported by NIH's Intramural Research Program (NIAAA) and by DOE (DE-AC01-76CH00016).
References (80)
Interactions between the “cognitive” and “metabolic” brain in the control of food intake
Physiol. Behav.
(2007)- et al.
Acute effects of cocaine on human brain activity and emotion
Neuron
(1997) - et al.
Prefrontal executive and cognitive functions in rodents: neural and neurochemical substrates
Neurosci. Biobehav. Rev.
(2004) - et al.
An affected pedigree member analysis of linkage between the dopamine D2 receptor gene TaqI polymorphism and obesity and hypertension
Int. J. Cardiol.
(2005) - et al.
Mood, eating attitudes, and anger in obese women with and without binge eating disorder
J. Psychosom. Res.
(2003) - et al.
Elevated body mass index is associated with executive dysfunction in otherwise healthy adults
Compr. Psychiatry
(2007) - et al.
Decreased striatal D2 dopamine receptors in obese Zucker rats: changes during aging
Brain. Res.
(1992) - et al.
Dopamine transporter and D2 receptor binding densities in mice prone or resistant to chronic high fat diet-induced obesity
Behav. Brain Res.
(2006) - et al.
D1 and D2 dopamine receptor mRNA expression in whole hemisphere sections of the human brain
J. Chem. Neuroanat.
(2001) Topographic projections in the globus pallidus and the substantia nigra of selectively placed lesions in the precommissural caudate nucleus and putamen in the monkey
Exp. Neurology
(1971)