Neural Systems & Behavior, Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, USA.
Bernstein Center for Computational Neuroscience Berlin, Humboldt-Universität zu Berlin, Philippstr. 13, Haus 6, 10115, Berlin, Germany.
Sci Rep. 2018 Sep 10;8(1):13556. doi: 10.1038/s41598-018-31710-0.
In mammals, a complex array of oral sensors assess the taste, temperature and haptic properties of food. Although the representation of taste has been extensively studied in the gustatory cortex, it is unclear how the somatosensory cortex encodes information about the properties of oral stimuli. Moreover, it is poorly understood how different oral sensory modalities are integrated and how sensory responses are translated into oral motor actions. To investigate whether oral somatosensory cortex processes food-related sensations and movements, we performed in vivo whole-cell recordings and motor mapping experiments in rats. Neurons in oral somatosensory cortex showed robust post-synaptic and sparse action potential responses to air puffs. Membrane potential showed that cold water evoked larger responses than room temperature or hot water. Most neurons showed no clear tuning of responses to bitter, sweet and neutral gustatory stimuli. Finally, motor mapping experiments with histological verification revealed an initiation of movements related to food consumption behavior, such as jaw opening and tongue protrusions. We conclude that somatosensory cortex: (i) provides a representation of the temperature of oral stimuli, (ii) does not systematically encode taste information and (iii) influences orofacial movements related to food consummatory behavior.
在哺乳动物中，一系列复杂的口腔传感器评估食物的味道、温度和触觉特性。尽管味觉在味觉皮层中的表现已经得到了广泛的研究，但目前尚不清楚感觉皮层如何编码关于口腔刺激物特性的信息。此外，不同口腔感觉模式如何整合以及感觉反应如何转化为口腔运动动作，这些问题也了解甚少。为了研究口腔感觉皮层是否处理与食物相关的感觉和运动，我们在大鼠中进行了体内全细胞记录和运动映射实验。口腔感觉皮层中的神经元对空气喷射表现出强烈的突触后和稀疏的动作电位反应。膜电位表明，冷水引起的反应大于室温或热水。大多数神经元对苦味、甜味和中性味觉刺激没有明显的反应调谐。最后，具有组织学验证的运动映射实验揭示了与食物消费行为相关的运动的启动，例如张口和舌头伸出。我们的结论是，感觉皮层：（i）提供了口腔刺激温度的表示，（ii）不系统地编码味觉信息，（iii）影响与食物摄食行为相关的口面运动。
