Human cortical representation of oral temperature

Center for Neurosensory Disorders, School of Dentistry, University of North Carolina, Chapel Hill, NC, United States.
Physiology & Behavior (Impact Factor: 2.98). 01/2008; 92(5):975-84. DOI: 10.1016/j.physbeh.2007.07.004
Source: PubMed


The temperature of foods and fluids is a major factor that determines their pleasantness and acceptability. Studies of nonhuman primates have shown that many neurons in cortical taste areas receive and process not only chemosensory inputs, but oral thermosensory (temperature) inputs as well. We investigated whether changes in oral temperature activate these areas in humans, or middle or posterior insular cortex, the areas most frequently identified for the encoding of temperature information from the human hand. In the fMRI study we identified areas of activation in response to innocuous, temperature-controlled (cooled and warmed, 5, 20 and 50 degrees C) liquid introduced into the mouth. The oral temperature stimuli activated the insular taste cortex (identified by glucose taste stimuli), a part of the somatosensory cortex, the orbitofrontal cortex, the anterior cingulate cortex, and the ventral striatum. Brain regions where activations correlated with the pleasantness ratings of the oral temperature stimuli included the orbitofrontal cortex and pregenual cingulate cortex. We conclude that a network of taste- and reward-responsive regions of the human brain is also activated by intra-oral thermal stimulation, and that the pleasant subjective states elicited by oral thermal stimuli are correlated with the activations in the orbitofrontal cortex and pregenual cingulate cortex. Thus the pleasantness of oral temperature is represented in brain regions shown in previous studies to represent the pleasantness of the taste and flavour of food. Bringing together these different oral representations in the same brain regions may enable particular combinations to influence the pleasantness of foods.

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    • "Interoception, pain, or emphatic feeling, but also awareness of body movement and emotions as well as speech, have been correlated with activations in the insular cortex (Craig, 2009). Thermal, (Craig et al., 2000; Guest et al., 2007), 0306-4522/Ó 2014 IBRO. Published by Elsevier Ltd. "
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    Neuroscience 05/2014; 273. DOI:10.1016/j.neuroscience.2014.05.017 · 3.36 Impact Factor
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    • "In addition to sensation of pleasant warm cutaneous stimuli, representations of a number of other pleasant stimuli are described in the medial-orbitofrontal cortex and pregenual cingulate cortex. These include oral warmth (Guest et al., 2007), the attractiveness "
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    ABSTRACT: Current theories suggest that the brain is the sole source of mental illness. However, affective disorders, and major depressive disorder (MDD) in particular, may be better conceptualized as brain-body disorders that involve peripheral systems as well. This perspective emphasizes the embodied, multifaceted physiology of well-being, and suggests that afferent signals from the body may contribute to cognitive and emotional states. In this review, we focus on evidence from preclinical and clinical studies suggesting that afferent thermosensory signals contribute to well-being and depression. Although thermoregulatory systems have traditionally been conceptualized as serving primarily homeostatic functions, increasing evidence suggests neural pathways responsible for regulating body temperature may be linked more closely with emotional states than previously recognized, an affective warmth hypothesis. Human studies indicate that increasing physical warmth activates brain circuits associated with cognitive and affective functions, promotes interpersonal warmth and prosocial behavior, and has antidepressant effects. Consistent with these effects, preclinical studies in rodents demonstrate that physical warmth activates brain serotonergic neurons implicated in antidepressant-like effects. Together, these studies suggest that (1) thermosensory pathways interact with brain systems that control affective function, (2) these pathways are dysregulated in affective disorders, and (3) activating warm thermosensory pathways promotes a sense of well-being and has therapeutic potential in the treatment of affective disorders.
    Frontiers in Psychology 01/2014; 5:1580. DOI:10.3389/fpsyg.2014.01580 · 2.80 Impact Factor
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    • "Villanova et al. (1997) established that cold and warm stimuli in the stomach were consciously perceived and suggests a role for the gastrointestinal tract in perception of temperature. It was subsequently documented that a small (3.5 ml) cold sensation in the mouth increased pleasantness and stimulated areas of the brain associated with reward/pleasure (Guest et al., 2007). It is therefore hypothesized that performance may be improved due to a reduced perception of body temperature and/or via increased central drive resulting from improved sensation of reward/pleasure. "
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