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Abstract Background In university health care settings, students with psychosomatic complaints often have chronotypic problems. For this reason, we investigated a potential connection between psychosomatic complaints and circadian rhythm irregularity assessed by salivary levels of melatonin and growth hormone. Methods Fifteen healthy students between 21 and 22 years of age were examined for physiological parameters of chronotypes based on melatonin and growth hormone secretion patterns, using a fluorescence enzyme immunoassay. Salivary samples were collected from subjects at home five times each day (20:00, 24:00, 04:00, 08:00, and 12:00 h). In addition, the subjects rated their psychosomatic symptoms twice (at 08:00 and 20:00 h). Results A group with irregular circadian rhythm of melatonin (ICR) showed more psychosomatic complaints than a group with the regular circadian rhythm (RCR), especially for anxiety. Conclusion Psychosomatic symptoms, particularly anxiety, may be associated with irregularity in melatonin and growth hormone rhythms, which can be altered by basic lifestyle habits even in healthy students.

Abstract Background Students suffering from psychosomatic symptoms, including drowsiness and feelings of melancholy, often have basic lifestyle problems. The aim of this study was to investigate whether psychosomatic complaints may be related to circadian dysfunction. Methods We examined 15 healthy students (4 men and 11 women) between 21 and 22 years old. To assess the presence of psychosomatic symptoms among the subjects, we developed a self-assessment psychosomatic complaints questionnaire consisting of five items pertaining to physical symptoms and five items concerning mental symptoms. The subjects rated their psychosomatic symptoms twice a day (08:00 and 20:00 h). We also assessed growth hormone secretion patterns by fluorescence enzyme immunoassay (FEIA). Salivary samples were collected from the subjects at home five times a day (20:00, 24:00, 04:00, 08:00, and 12:00 h) in Salivette tubes. Results The results indicated a relationship between the self-assessment scores and the salivary levels of growth hormone. Subjects with high self-assessment scores showed significant variability in growth hormone secretion over the day, whereas subjects with low self-assessment scores did not. Conclusion Psychosomatic symptoms may be associated with circadian dysfunction, as inferred from blunted rhythmicity in growth hormone secretion.

The network mechanisms underlying how inhibitory circuits regulate ON‐ and OFF‐responses (the b‐ and d‐waves) in the electroretinogram (ERG) remain unclear. The purpose of this study was to investigate the contribution of inhibitory circuits to the emergence of the b‐ and d‐waves in the full‐field ERG in the newt retina. To this end, we investigated the effects of several synaptic transmission blockers on the amplitudes of the b‐ and d‐waves in the ERG obtained from newt eyecup preparations. Our results demonstrated that (a) L‐APB blocked the b‐wave, indicating that the b‐wave arises from the activity of ON‐bipolar cells (BCs) expressing type six metabotropic glutamate receptors; (b) the combined administration of UBP310/GYKI 53655 blocked the d‐wave, indicating that the d‐wave arises from the activity of OFF‐BCs expressing kainate‐/AMPA‐receptors; (c) SR 95531 augmented both the b‐ and the d‐wave, indicating that GABAergic lateral inhibitory circuits inhibit both ON‐ and OFF‐BC pathways; (d) the administration of strychnine in the presence of SR 95531 attenuated the d‐wave, and this attenuation was prevented by blocking ON‐pathways with L‐APB, which indicated that the glycinergic inhibition of OFF‐BC pathway is downstream of the GABAergic inhibition of the ON‐system; and (e) the glycinergic inhibition from the ON‐ to the OFF‐system widens the response range of OFF‐BC pathways, specifically in the absence of GABAergic lateral inhibition. Based on these results, we proposed a circuitry mechanism for the regulation of the d‐wave and offered a tentative explanation of the circuitry mechanisms underlying ERG formation. [ABSTRACT FROM AUTHOR]

The purpose of this pilot study was to explore the lifestyle of today's youth by identifying characteristics of melatonin and cortisol that affect biological rhythms in university students. We investigated the relationships between morning cortisol levels and psychosomatic conditions to examine the effects of biological rhythm on psychosomatic conditions and daytime sleepiness. To analyse biological rhythms, salivary melatonin and cortisol levels were measured by a fluorescence enzyme immunoassay. We determined that (1) the biological rhythms of melatonin and cortisol have important effects on students' daytime psychosomatic conditions and (2) morning cortisol levels are associated with daytime psychosomatic conditions. In contrast, although some positive correlations between morning cortisol levels and mental symptoms after napping (feelings of melancholy, anxiety) were confirmed, no correlation with physical symptoms was identified. [ABSTRACT FROM AUTHOR]

In an effort to improve school performance, we have examined the effect of sleep–wake patterns, particularly time in bed, and morning psychosomatic conditions in adolescents. A psychosomatic disorder questionnaire was administered to 135 physically healthy students, who were divided into four groups according to time they went to bed: 23–24, 24–01, 01–02 and 02–03 h. (1) The 23–24 and 24–01 h groups had significantly higher grade point averages than the 02–03 h group. (2) Partial correlations, controlling for sleep quality, revealed significant associations between time to bed and psychosomatic disorder, with regard to whole-body fatigue, lack of motivation and the desire to rest. Our results suggest that the sleep–wake pattern, especially the time of retiring, may predict academic performance and psychosomatic disorder. [ABSTRACT FROM PUBLISHER]

Students suffering from subjective psychosomatic disorder often have basic lifestyle problems. We examined 30 healthy students aged 21–22 years old. Salivary samples were collected from the subjects at home five times per day (20:00, 24:00, 04:00, 08:00 and 12:00 h). We assessed melatonin secretion patterns by fluorescence enzyme immunoassay and cortisol secretion by ELISA. We assigned the subjects to regular, semi-regular and irregular circadian rhythm groups based on whether melatonin secretion was high until midnight. A self-assessment questionnaire addressing psychosomatic disorder was completed by the same students. The subjects rated their psychosomatic symptoms twice per day (08:00 and 20:00 h). The irregular group showed lower cortisol awakening response, but high cortisol concentrations at 12:00 h; this group also reported more subjective health complaints related to psychosomatic stress compared with the regular group. Our findings suggest that psychosomatic disorder is associated with circadian rhythms in Japanese students. [ABSTRACT FROM PUBLISHER]