Objective:Self-touch is thought to be an act of coping with harmful or stressful situations, based on the mechanism which suppresses somatosensory perception as well as somatosensory cortex activity, and sympathetic activity. In addition, this suppression can be observed in even nonpainful and non-stressful situations. However, its detailed neural mechanism remains unknown. Several studied have shown, not only that the descending pain modulatory system (DPMS) plays critical roles in painful situations, but also that there is intrinsic functional connectivity in the DPMS in even non-painful situations. Based on these findings, we hypothesized that the neural system consisting of the anterior cingulate cortex (ACC), amygdala and rostral ventromedial medulla (RVM) would play a basic role in self-touch, and we here investigated interactive effects of these regions in a pain-free self-touch situation. Methods:We used functional magnetic resonance imaging (fMRI) to investigate brain activity induced by mere self-touch (rubbing the left hand with the right) in a pain-free and stress-free situation, and carried out the Physio-Physiological Interaction (PPI) analysis to investigate the modulatory effects of brain activity. Results:PPI analysis showed that the rostral ACC (rACC) modulated activity in the RVM and left cerebellum (CB) via the right amygdala, such that the modulation linearly suppressed RVM and left CB activity. Furthermore, the latter was positively correlated with right primary somatosensory cortex (SI) activity. Moreover, we also showed that coherent activity in the bilateral secondary somatosensory cortex (SII) modulated activity of both the left temporoparietal junction (TPJ) and RVM, with the latter also suppressed by the modulation in a linear fashion. Conclusion:These findings suggest that self-touch exerts inhibitory effects on sensory afferents and sympathetic activity through the ACC-amygdala-RVM (AAR) system, and that bilateral sensorimotor integration plays an important role in the effect based on the bodily self.

The effects of the sample matrix on the separation of peptides by HPCE has been investigated. Under both acidic and alkaline conditions, use of 25–30 mM salts in the sample zone resulted in much better resolution than did 100 mM salts. Prefocusing effects and acceleration of elution were also observed. These results agree well with the theory developed by Everaerts. In this paper a practical guide for high sensitivity, high resolution separation of salt‐containing peptide mixtures is proposed.

Touch is a primary reinforcer strongly associated with motivational and affective processes that drive social behavior, and it also plays a critical role in massage therapy. Touch in massage is characterized by gentle touches of the skin involving light pressure effleurage and calm stroking movements intended to increase recipients' pleasure and relaxation. The relationships between basic physical parameters, such as patterns of the hand movements, and their neural bases are important for understanding the effects of gentle touch. However, such studies have not yet been performed. Here, we investigated these relationships and underlying neural mechanisms under two basic movement conditions. Methods Using functional Magnetic Resonance Imaging (fMRI), we investigated brain activity induced by Circular (C) and Back-and-forth (BF) massage of participants' left hands with the experimenter's right hand, ensuring that movements were not unpleasant. We assessed subjective feelings, and analyzed fMRI data with Principal Component Analysis (PCA) and correlation analyses to identify associated brain networks. Results In C compared with BF, participants felt more positive emotions. There was greater activation of the right primary Somatosensory Cortex (SI) and left cerebellum (CB), but lower activation of the Anterior Cingulate Cortex (ACC) and Periaqueductal Gray (PAG) in C compared with BF. There was no significant difference in unpleasant feelings between the conditions. Moreover, co-activation of the left mid-lateral Orbitofrontal Cortex (OFC), CB, and Rostral Ventromedial Medulla (RVM), and the right SI and posterior insula showed high loadings on Factor 1, which was negatively correlated with unnatural feelings. Meanwhile, co-activation of the ACC and PAG showed high loadings on Factor 2, which was positively correlated with unpleasant feelings. Conclusion Our findings suggest somatosensory afferents to the SI are regulated by the descending pain modulatory system under the control of the mid-lateral OFC and ACC, even with mild somatosensory stimulation.

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Texture of the cosmetic products is an important factor for the consumer satisfaction. It is considered that the texture is originated from various physical properties. However, since the phenomena are very complicated, to appropriate quantification is difficult. Our attempt is to quantify the texture of the initial touch of the cosmetics by studying the rheological properties. Flow properties of cosmetic lotions, containing various kinds of aqueous thickeners, were studied by creep measurement, and parameters a, b, and j, were calculated from their rheological data based on the Nutting equation, which is an empirical equation. As another approach, sensory evaluation test of the cosmetic samples was carried out by human panels. There were some correlations among the time dependency parameter a and some sensory evaluation points, assessed by human panels. Simple linear regression analysis revealed that the evaluation scores of slimy feeling, sticky feeling, refresh feeling, and penetrating feeling of the cosmetic lotions were converted to numerical data by the parameter a. This quantification method for the texture of cosmetic products will be a useful tool for efficient development of cosmetic formulations. It is possible to estimate the texture of the products by studying the rheological value a.