Transient expansion of the expression region of Hsd11b1, encoding 11 β‐hydroxysteroid dehydrogenase type 1, in the developing mouse neocortex

AbstractCorticosteroids are stress-related hormones that maintain homeostasis. The most effective corticosteroids are corticosterone (CORT) in rodents and cortisol in primates. 11 β-Hydroxysteroid dehydrogenase type 1 (11β-HSD1; EC 1.1.1.146), encoded byHsd11b1, is a key regulator of the local concentration of CORT/cortisol.Hsd11b1 expression in layer 5 of the primary somatosensory cortex has been shown in adult mice. However, its localization in the entire neocortex, especially during development, has not been fully addressed. Here, we established robust and dynamic expression profiles ofHsd11b1 in the developing mouse neocortex.Hsd11b1 was found mostly in pyramidal neurons. By retrograde tracing, we observed that someHsd11b1-positive cells were projection neurons, indicating that at least some were excitatory. At postnatal day 0 (P0),Hsd11b1 was expressed in the deep layer of the somatosensory cortex. Then, from P3 to P8, the expression area expanded broadly; it was observed in layers 4 and 5, spanning the whole neocortex, including the primary motor cortex (M1) and the primary visual cortex (V1). The positive region gradually narrowed from P14 onward and was ultimately limited to layer 5 of the somatosensory cortex at P26 and later. Furthermore, we administered CORT to nursing dams to increase the systemic CORT level of their pups. Here, we observed a reduced number ofHsd11b1-positive cells in the neocortex of these pups. Our observation suggests thatHsd11b1 expression i...
Source: Journal of Neurochemistry - Category: Neuroscience Authors: Tags: ORIGINAL ARTICLE Source Type: research