Limits...
The use of functional MRI to study appetite control in the CNS.

De Silva A, Salem V, Matthews PM, Dhillo WS - Exp Diabetes Res (2012)

Bottom Line: In the present absence of any safe or effective centrally acting appetite suppressants, a better understanding of how appetite is controlled is vital for the development of new antiobesity pharmacotherapies.Early functional imaging techniques revealed an attenuation of brain reward area activity in response to visual food stimuli when humans are fed-in other words, the physiological state of hunger somehow increases the appeal value of food.The hypothalamus acts as a central gateway modulating homeostatic and nonhomeostatic drives to eat.

View Article: PubMed Central - PubMed

Affiliation: Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.

ABSTRACT
Functional magnetic resonance imaging (fMRI) has provided the opportunity to safely investigate the workings of the human brain. This paper focuses on its use in the field of human appetitive behaviour and its impact in obesity research. In the present absence of any safe or effective centrally acting appetite suppressants, a better understanding of how appetite is controlled is vital for the development of new antiobesity pharmacotherapies. Early functional imaging techniques revealed an attenuation of brain reward area activity in response to visual food stimuli when humans are fed-in other words, the physiological state of hunger somehow increases the appeal value of food. Later studies have investigated the action of appetite modulating hormones on the fMRI signal, showing how the attenuation of brain reward region activity that follows feeding can be recreated in the fasted state by the administration of anorectic gut hormones. Furthermore, differences in brain activity between obese and lean individuals have provided clues about the possible aetiology of overeating. The hypothalamus acts as a central gateway modulating homeostatic and nonhomeostatic drives to eat. As fMRI techniques constantly improve, functional data regarding the role of this small but hugely important structure in appetite control is emerging.

Show MeSH

Related in: MedlinePlus

Brain reward centres: the hypothalamus (H), as a homeostatic gatekeeper, has numerous connections with higher brain centres which process salience and reward. The hypothalamus transmits to these higher centres information received from the periphery, such as nutritional status signalled via the postprandial release of gut hormones, and in turn modulates metabolic rate via the sympathetic nervous system. This sagittal section of the brain reveals the important areas involved in the hedonic control of eating behaviour; amygdale (Am): emotional and aversive processing; nucleus accumbens (Nac): anticipatory reward processing; ventral tegmental area (VTA): numerous dopaminergic projections to other limbic areas; ventral striatum (VS): motivation reward; expectancy and novelty processing; anterior cingulate cortex (ACC): decision making; orbitofrontal cortex (OFC): reward encoding; prefrontal cortex (PFC): translation of external and internal cues into behavioural responses; dorsolateral prefrontal cortex (DLPFC): self-control. Not shown is the insular cortex (a more lateral structure), which is also important in gustatory processing.
© Copyright Policy - open-access
Related In: Results  -  Collection


getmorefigures.php?uid=PMC3376546&req=5

fig1: Brain reward centres: the hypothalamus (H), as a homeostatic gatekeeper, has numerous connections with higher brain centres which process salience and reward. The hypothalamus transmits to these higher centres information received from the periphery, such as nutritional status signalled via the postprandial release of gut hormones, and in turn modulates metabolic rate via the sympathetic nervous system. This sagittal section of the brain reveals the important areas involved in the hedonic control of eating behaviour; amygdale (Am): emotional and aversive processing; nucleus accumbens (Nac): anticipatory reward processing; ventral tegmental area (VTA): numerous dopaminergic projections to other limbic areas; ventral striatum (VS): motivation reward; expectancy and novelty processing; anterior cingulate cortex (ACC): decision making; orbitofrontal cortex (OFC): reward encoding; prefrontal cortex (PFC): translation of external and internal cues into behavioural responses; dorsolateral prefrontal cortex (DLPFC): self-control. Not shown is the insular cortex (a more lateral structure), which is also important in gustatory processing.

Mentions: With regard to “nonhomeostatic” control, food intake is driven by factors including food palatability (incorporating the key senses of sight, smell, and taste), habitual, socio-cultural, emotional, and economic influences. From an emotional perspective, the evaluation of a food stimulus for its motivational significance occurs in multiple brain regions, particularly the dopaminergic limbic and prefrontal reward areas [7]. Key areas include the amygdala, hippocampus, insula, striatum, and orbitofrontal cortex (OFC), although this list is by no means exhaustive. It is now widely accepted that, with regard to appetite control, homeostatic and nonhomeostatic systems do not function independently; instead, there is extensive cross-modulation between them, along with a complex integration of inputs before a final decision is made regarding food consumption (Figure 1).


The use of functional MRI to study appetite control in the CNS.

De Silva A, Salem V, Matthews PM, Dhillo WS - Exp Diabetes Res (2012)

Brain reward centres: the hypothalamus (H), as a homeostatic gatekeeper, has numerous connections with higher brain centres which process salience and reward. The hypothalamus transmits to these higher centres information received from the periphery, such as nutritional status signalled via the postprandial release of gut hormones, and in turn modulates metabolic rate via the sympathetic nervous system. This sagittal section of the brain reveals the important areas involved in the hedonic control of eating behaviour; amygdale (Am): emotional and aversive processing; nucleus accumbens (Nac): anticipatory reward processing; ventral tegmental area (VTA): numerous dopaminergic projections to other limbic areas; ventral striatum (VS): motivation reward; expectancy and novelty processing; anterior cingulate cortex (ACC): decision making; orbitofrontal cortex (OFC): reward encoding; prefrontal cortex (PFC): translation of external and internal cues into behavioural responses; dorsolateral prefrontal cortex (DLPFC): self-control. Not shown is the insular cortex (a more lateral structure), which is also important in gustatory processing.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC3376546&req=5

fig1: Brain reward centres: the hypothalamus (H), as a homeostatic gatekeeper, has numerous connections with higher brain centres which process salience and reward. The hypothalamus transmits to these higher centres information received from the periphery, such as nutritional status signalled via the postprandial release of gut hormones, and in turn modulates metabolic rate via the sympathetic nervous system. This sagittal section of the brain reveals the important areas involved in the hedonic control of eating behaviour; amygdale (Am): emotional and aversive processing; nucleus accumbens (Nac): anticipatory reward processing; ventral tegmental area (VTA): numerous dopaminergic projections to other limbic areas; ventral striatum (VS): motivation reward; expectancy and novelty processing; anterior cingulate cortex (ACC): decision making; orbitofrontal cortex (OFC): reward encoding; prefrontal cortex (PFC): translation of external and internal cues into behavioural responses; dorsolateral prefrontal cortex (DLPFC): self-control. Not shown is the insular cortex (a more lateral structure), which is also important in gustatory processing.
Mentions: With regard to “nonhomeostatic” control, food intake is driven by factors including food palatability (incorporating the key senses of sight, smell, and taste), habitual, socio-cultural, emotional, and economic influences. From an emotional perspective, the evaluation of a food stimulus for its motivational significance occurs in multiple brain regions, particularly the dopaminergic limbic and prefrontal reward areas [7]. Key areas include the amygdala, hippocampus, insula, striatum, and orbitofrontal cortex (OFC), although this list is by no means exhaustive. It is now widely accepted that, with regard to appetite control, homeostatic and nonhomeostatic systems do not function independently; instead, there is extensive cross-modulation between them, along with a complex integration of inputs before a final decision is made regarding food consumption (Figure 1).

Bottom Line: In the present absence of any safe or effective centrally acting appetite suppressants, a better understanding of how appetite is controlled is vital for the development of new antiobesity pharmacotherapies.Early functional imaging techniques revealed an attenuation of brain reward area activity in response to visual food stimuli when humans are fed-in other words, the physiological state of hunger somehow increases the appeal value of food.The hypothalamus acts as a central gateway modulating homeostatic and nonhomeostatic drives to eat.

View Article: PubMed Central - PubMed

Affiliation: Division of Diabetes, Endocrinology and Metabolism, Imperial College London, Hammersmith Hospital Campus, Du Cane Road, London W12 0NN, UK.

ABSTRACT
Functional magnetic resonance imaging (fMRI) has provided the opportunity to safely investigate the workings of the human brain. This paper focuses on its use in the field of human appetitive behaviour and its impact in obesity research. In the present absence of any safe or effective centrally acting appetite suppressants, a better understanding of how appetite is controlled is vital for the development of new antiobesity pharmacotherapies. Early functional imaging techniques revealed an attenuation of brain reward area activity in response to visual food stimuli when humans are fed-in other words, the physiological state of hunger somehow increases the appeal value of food. Later studies have investigated the action of appetite modulating hormones on the fMRI signal, showing how the attenuation of brain reward region activity that follows feeding can be recreated in the fasted state by the administration of anorectic gut hormones. Furthermore, differences in brain activity between obese and lean individuals have provided clues about the possible aetiology of overeating. The hypothalamus acts as a central gateway modulating homeostatic and nonhomeostatic drives to eat. As fMRI techniques constantly improve, functional data regarding the role of this small but hugely important structure in appetite control is emerging.

Show MeSH
Related in: MedlinePlus