Association between changes in cortical and jaw motor activities during sleep

In normal sleep, cortical EEG activity is influenced by the balance in the activities of subcortical neurons in relation to the cyclic changes of sleep states. As well, jaw motor excitability is altered under the activity of sleep regulatory mechanism. Transient arousals (e.g., micro-arousal) are associated with a brief change of cortical activity and an increase of jaw motor activity. During this period, various types of jaw motor activities are occasionally found to occur, with either non-specific or specific patterns such as rhythmic activations. Exaggeration of the jaw motor activities during sleep can be seen in patients with sleep bruxism. Although cortical activity reflects arousal level and is correlated with the activity level of jaw muscles during sleep, it remains to be investigated whether or not cortex plays one of the sources of descending excitatory drive shaping a variety of jaw motor activities.     

Interleukin-6-producing dermoid cyst associated with multicentric Castleman’s disease

Dysregulated overproduction of interleukin-6 (IL-6) from activated B cells in affected lymph nodes has been implicated in the pathogenesis of multicentric Castleman’s disease (MCD), a rare lymphoproliferative disorder accompanied by systemic manifestations. We here report the case of a 32-year-old female presenting with MCD associated with a dermoid cyst in the pelvic cavity. The co-occurrence of MCD and dermoid cyst has not been reported before. Immunohistochemical analysis of the tissue sections showed IL-6 production in CD68-positive macrophage cells, which had infiltrated the dermoid cyst. Removal of the cyst resulted in partial improvement in systemic symptoms accompanied by a decrease in serum IL-6, while complete improvement was obtained by treatment with an anti-IL-6 receptor antibody following resection of the dermoid cyst. To the best of our knowledge, this is the first study to provide evidence of IL-6 production by CD68⁺ cells in a dermoid cyst involved in MCD.     

Immunocytochemical localization of kisspeptin neurons in the rat forebrain with special reference to sexual dimorphism and interaction with GnRH neurons

Kisspeptin/metastin has been implicated as a critical regulator in luteinizing hormone (LH) secretion and the reproductive system mediating the effect of estrogen on GnRH neurons. In the present study we examined the sex differences in the effects of estrogen on Kiss1/kisspeptin expression in the forebrain by using gonadectomized rats to assess the interaction of kisspeptin and GnRH neurons. Kiss1/kisspeptin cell bodies were abundant in the rostral periventricular area of the third ventricle (RV3P) and the arcuate nucleus (ARC). A few cell bodies were also observed in other portions of the forebrain, i.e. the bed nucleus of the stria terminalis (BST), the paraventricular hypothalamic nucleus (PaAP), the ventromedial hypothalamic nucleus (VMH), and the medial amygdaloid nucleus (MeA). Kisspeptin-immunoreactive fibers were found mainly in the median eminence (ME), the ARC, and the RV3P, but were scarce in the preoptic area (POA), where GnRH neurons are localized. We also found that estrogen triggers expression of the Kiss1 gene and peptide within all the regions except the ARC, and that the effects in the RV3P, BST, PaAP, and VMH are greater in estrogen treated ovariectomized female rat. It is noteworthy that kisspeptin and GnRH neurons were densely associated in the ME but were rarely in contact in the POA. Thus, our results suggest that kisspeptin-positive neurons, except for the ones in the ARC, are related not only to estrogen-positive feedback, but also sex dimorphism, and that kisspeptin regulates GnRH release in the ME rather than the POA.