Page 33 - Nutrinsight-4

NutrInsight • Satiety: News Insights
A 8 6 4 2 0
D
E
F
Hunger level
B
8 4 0 -4
C
Odor pleasantness 2(UCS) devaluation
Scanning Session 1 Scanning Session 2 food deprived devalued Tgt UCS
Satiation on meal with the target odor
Differential responses to Tgt CS+ from pre-to post satiety,
relative to non-Tgt CS+
Non-Target CS+ gains strength
> Dessert becomes more desirable?
Before meal
After meal
First After bite meal
0 -2 -4 -8
2 0 -2
1 0 -1 -2
Tgt nTgt UCS UCS
Amygdala
Tgt nTgt CS+u CS+u
Orbitofrontal cortex
3 0 -3
Vent. striatum Insula
Tgt nTgt CS+u CS+u
Cingulate cortex
Tgt nTgt CS+u CS+u
Tgt CS+u
nTgt Tgt nTgt CS+u CS+u CS+u
Figure 2: In a paradigm of appetitive olfactory learning, arbitrary pictures constituted the target (Tgt)
and non-target (nTgt) CS+ stimuli.
(A to C) Mean behavioral ratings of hunger level (A), food pleasantness (B), and odor pleasantness (C) illustrating selective devaluation of the target uCS.
(D to F) Satiety-sensitive neural activations that paralleled the behavioral effect. (D to E) In dorsomedial amygdala and orbitofrontal cortex (oFC), neural responses elicited by the target CS+u declined from pre- to post- satiety, whereas non- target CS+u activity was unchanged. (F) By comparison, significant satiety-related effects in ventral striatum (vst), insula (ins), and anterior cingulate (cg) also reflected response increases to the non-target CS+u.
Source: Adapted from Gottfried et al., 2003
After initial training in the hungry state, participants were fed to satiety with a meal corresponding to the target odor, thereby reducing the motivational value of the target UCS without affecting non-target UCS value. Pleasantness ratings from pre- to post-feeding decreased for the target UCS, but no change occurred for the non-target odor. In parallel, significant response decrements occurred in the left dorsomedial amygdala and significant differential activity was detected in multiple areas of the orbitofrontal cortex (Figure 2 D, E)
These changes demonstrated satiety-related declines in target CS+u activity with preserved non-target CS+u activity. By contrast, satiety-sensitive neural responses in the ventral striatum, insula, and anterior cingulate exhibited a different pattern of activity, reflecting both decreases to the target CS+u and increases to the non-target CS+u. This suggests that, following selective satiation on one food item, the relative reward value of other foods might be enhanced. This observation agrees with human appetite studies showing that the pleasantness of an unsated food can increase at the same time that sated items become less appetizing. It has been hypothesized that shifting the balance of reward representation from consumed to unconsumed foods may optimize the motivational basis for food selection [Gottfried et al., 2003].
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Hunger level (0 to +10)
Beta (Post + Pre)
Food pleasantness (-10 to +10)
Beta (Post + Pre)
Beta (Post + Pre)
Odor pleasantness (Post + Pre)