Brain mechanisms underlying flavour and appetite
Tóm tắt
Complementary neurophysiological recordings in macaques and functional neuroimaging in humans show that the primary taste cortex in the rostral insula and adjoining frontal operculum provides separate and combined representations of the taste, temperature and texture (including viscosity and fat texture) of food in the mouth independently of hunger and thus of reward value and pleasantness. One synapse on, in the orbitofrontal cortex, these sensory inputs are for some neurons combined by learning with olfactory and visual inputs. Different neurons respond to different combinations, providing a rich representation of the sensory properties of food. In the orbitofrontal cortex, feeding to satiety with one food decreases the responses of these neurons to that food, but not to other foods, showing that sensory-specific satiety is computed in the primate (including human) orbitofrontal cortex. Consistently, activation of parts of the human orbitofrontal cortex correlates with subjective ratings of the pleasantness of the taste and smell of food. Cognitive factors, such as a word label presented with an odour, influence the pleasantness of the odour and the activation produced by the odour in the orbitofrontal cortex. These findings provide a basis for understanding how what is in the mouth is represented by independent information channels in the brain; how the information from these channels is combined; and how and where the reward and subjective affective value of food is represented and is influenced by satiety signals. Activation of these representations in the orbitofrontal cortex may provide the goal for eating, and understanding them helps to provide a basis for understanding appetite and its disorders.
Từ khóa
Tài liệu tham khảo
Norgren R, 1984, Sensory processes 1, 1087
Rolls B.J, 1989, Handbook of the psychophysiology of human eating, 57
Rolls E.T, 1994, Appetite: neural and behavioural bases, 11, 10.1093/acprof:oso/9780198547877.003.0002
Rolls E.T The brain and emotion. 1999 Oxford UK:Oxford University Press.
Rolls E.T, 2000, Neural and metabolic control of macronutrient intake, 247
Rolls E.T, 1977, Food intake and chemical senses, 525
Rolls E.T, 1982, Psychobiology of human food selection, 33
Rolls E.T, 2003, Handbook of olfaction and gustation, 2, 679
Scott T.R, 1995, Brain mechanisms of satiety and taste in macaques, Neurobiology, 3, 281