Purpose: To evaluate convex gradient optimization (CVX) for increased spatiotemporal resolution and improved accuracy for phase-contrast MRI (PC-MRI).

我 々 は こ れ まで に、TGF 一βフ ァ ミ リーの 分泌 因子 で あ る Gdf11 や Activinβ B が 嗅覚上 皮 の 発 生 を負 に 制御す る こ とを見出 した 。 さ らに 、転 写因了一Foxg1 が TGF 一βフ ァ ミ リーの 分 泌 因 子 Gdfl1 の 活性制御 を通 じて 嗅覚上 皮 の 発 生 に 関与 す る こ と を、マ ウ ス の 遺伝学的 手 法 を用 い て 発 見 し た。こ れ らの 結 果 は 、Foxg1 と フ ォ リス タ チ ン （Fst）を介 した、Gdfl・1 の 「負の フ ィ ー ドバ ッ ク機構」の 適 切な制御が 、嗅覚上 皮 の 層構 造 形 成 （histogcnesis）お よ び 鼻甲介形成 （morphogcnesis ）の 両 方 に 重 要 で あ る が 、そ の 制 御 機構 に は 差 異が あ る こ とを示 して い る 。 / It has so far, it was found that TGF-β family of secreted factors and is Gdf11 and ActivinβB to control the negative occurrence of the olfactory epithelium. In addition, the transcription factor Foxg1 is to be involved in the development of the olfactory epithelium through active control of secreted factors Gdf11 of the TGF-β family, was discovered using genetic techniques in mice. These results, through the Foxg1 and follistatin (Fst), appropriate control of the "negative feedback mechanism" of Gdf11 is, important to both of the layer structure formation of the olfactory epithelium (histogenesis) and nasal turbinates formation (morphogenesis) although, it is shown that there are differences in the control mechanism.

The mouse olfactory epithelium (OE) is an ideal model system for identifying and characterizing the factors that regulate proliferation and differentiation of neurons from their stem and progenitor cells. In part, this is because the OE undergoes neurogenesis throughout life, and does so exuberantly in response to injury (Graziadei and Monti Graziadei 1978; Mackay-Sim and Kittel 1991; Calof et al. 2002). However, another advantage of great significance is the fact that numerous studies have given us a good idea of the cell types that give rise to olfactory receptor neurons (ORNs) (Cau et al. 1997; Calof et al. 2002; Kawauchi et al. 2004, 2005; Beites et al. 2005; see also Chapter 5). Thus, in the neuronal lineage of the OE, four cell stages have been identified, in vitro and in vivo: (1) Sox2-expressing stem cells, which reside in the basal compartment of the epithelium, are thought to commit to the ORN lineage via expression of the proneural gene, Mash1. (2) Mash1-expressing early progenitor cells, which divide and may act as transit-amplifying cells (Gordon et al. 1995), in turn give rise to (3) late-stage transit-amplifying cells, also known as immediate neuronal precursors (INPs), which express a second proneural gene, Ngn1 (Wu et al. 2003). INPs give rise to daughter cells that undergo terminal differentiation into (4) postmitotic Ncam-expressing ORNs. Figure 10.1A shows schematics of both the OE neuronal lineage and the spatial distribution of these cells within the OE in vivo. As is common to many epithelia, differentiation in the OE proceeds in a basal-to-apical direction: dividing stem and progenitor cells lie atop the basal lamina, and multiple layers of differentiated ORNs lie above the progenitor cells layers.