SummaryNinety percent of Americans consume less than the estimated average requirements of dietary vitamin E (vitE). Severe vitE deficiency due to genetic mutations in the tocopherol transfer protein (TTPA) in humans results in ataxia with vitE deficiency (AVED), with proprioceptive deficits and somatosensory degeneration arising from dorsal root ganglia neurons (DRGNs). Single-cell RNA-sequencing of DRGNs was performed in Ttpa−/− mice, an established model of AVED. In stark contrast to expected changes in proprioceptive neurons, Ttpa−/− DRGNs showed marked upregulation of voltage-gated Ca2+ and K+ channels in mechanosensitive, tyrosine-hydroxylase positive (TH+) DRGNs. The ensuing significant conductance changes resulted in reduced excitability in mechanosensitive Ttpa−/− DRGNs. A highly supplemented vitE diet (600 mg dl-α-tocopheryl acetate/kg diet) prevented the cellular and molecular alterations and improved mechanosensation. VitE deficiency profoundly alters the molecular signature and functional properties of mechanosensitive TH+ DRGN, representing an intriguing shift of the prevailing paradigm from proprioception to mechanical sensation.

Objective:The purpose of this study was to investigate the morphology and number of roots of Korean mandibular third molars, and to evaluate the prevalence of C-shaped, two-rooted, and three-rooted mandibular third molars using cone-beam computed tomography (CBCT).Materials and Methods:Serial axial CBCT images of the mandibles were gathered from 137 Korean patients. The total number of roots in the mandibular third molars of these patients was measured, and both the incidence and the correlations between left- and right-side occurrences, as well as between males and females, were analyzed.Results:Most of the mandibular third molars either had two roots (56.5%) or one root (37.9%). There was no significant difference regarding the incidence of the different types of roots according to gender (female versus male) or topology (right versus left side). A higher percentage (80.5%) of the patients had similar root morphology on both sides.Conclusion:The morphology and number of 214 mandibular third molars were examined using CBCT. There was a high prevalence of two-rooted mandibular and one-rooted mandibular third molars from this Korean population. Even though the anatomical variations in the mandibular third molars may not be high, these data regarding the occurrence and morphology of the roots will provide useful information to dentists performing these procedures.

The aim of this study is to investigate prevalence of irritable bowel syndrome (IBS) among adolescents and difference in worry and stress between normal and IBS groups. Questionnaire survey was conducted at a girl's middle and high school. Students from seventh to eleventh grade participated in the examination on Rome II criteria, lifestyle and dietary habits. Worry and stress were measured with the Korean version Penn State Worry Questionnaire-Children and the Korean version Brief Encounter Psychosocial Instrument. Worry score was significantly higher in the IBS group (22.07 ± 9.38, P < 0.001) than in the normal group (18.65 ± 8.99) and was higher in high school students than in middle school students (P = 0.02). Stress score also was higher in the IBS group than in the normal group (P < 0.001) and was higher in the high school girls than in the middle school ones (P = 0.04). Of all the lifestyle factors influencing IBS preference for fatty foods, preference for salty foods, drinking alcohol and sleeping for less than six hours a day were found to be significant. Worry and stress seem to be associated with IBS symptoms. The findings of this study draw a clue that less worry and stress will help decrease IBS symptoms.

Potassium (K + ) channels shape the response properties of neurons. Although enormous progress has been made to characterize K + channels in the primary auditory neurons, the molecular identities of many of these channels and their contributions to hearing in vivo remain unknown. Using a combination of RNA sequencing and single molecule fluorescent in situ hybridization, we localized expression of transcripts encoding the sodium-activated potassium channels K Na 1.1 (SLO2.2/Slack) and K Na 1.2 (SLO2.1/Slick) to the primary auditory neurons (spiral ganglion neurons, SGNs). To examine the contribution of these channels to function of the SGNs in vivo , we measured auditory brainstem responses in K Na 1.1/1.2 double knockout (DKO) mice. Although auditory brainstem response (wave I) thresholds were not altered, the amplitudes of suprathreshold responses were reduced in DKO mice. This reduction in amplitude occurred despite normal numbers and molecular architecture of the SGNs and their synapses with the inner hair cells. Patch clamp electrophysiology of SGNs isolated from DKO mice displayed altered membrane properties, including reduced action potential thresholds and amplitudes. These findings show that K Na 1 channel activity is essential for normal cochlear function and suggest that early forms of hearing loss may result from physiological changes in the activity of the primary auditory neurons.