Preseismic atmospheric radon anomaly associated with 2018 Northern Osaka earthquake.

Despite the challenges in identifying earthquake precursors in intraplate (inland) earthquakes, various hydrological and geochemical measurements have been conducted to establish a possible link to seismic activities. Anomalous increases in radon (Rn) concentration in soil, groundwater, and atmosphere have been reported prior to large earthquakes. Although the radon concentration in the atmosphere is lower than that in groundwater and soils, a recent statistical analysis has suggested that the average atmospheric concentration over a relatively wide area reflects crustal deformation.

Postnatal development of brainstem serotonin-containing neurons projecting to lumbar spinal cord in rats.

We quantified postnatal changes in brainstem serotonin (5-hydroxytryptamine, 5-HT)-containing neurons projecting to lumbar spinal cord. The medulla-spinal cord descending neurons were identified by a retrograde neurotracer, choleratoxin B subunit (CTb), and 5-HT neurons were stained by immunohistochemistry. Double-labeled neurons were assumed to be 5-HT neurons projecting to the lumbar spinal cord, and were quantitatively analyzed in each raphe nucleus in the medulla.