FGF10对内囊中丘脑皮质轴突和新生血管的导向作用

The internal capsule of the ventral telencephalon is an organization rich of neural fibers and blood vessels. In the ventral telencephalon, the major ascending and descending neural fibers are thalamocortical, corticobulbar and corticospinal axons. The blood supply of the ventral telencephalan is majorly from the Lenticulostriate artery, a branch of the middle cerebral artery. The area of the ventral telencephalon is the most common site for the intracerebral hemorrhages, causing the typical symptoms of hemiparesis or hemiplegia. Much evidence suggests a common mechanism for axonal and vascular guidance. Many reports show that, just as classical guidance cues (ephrins, slits, semaphorins and netrins), morphogens of FGFs can help both axons and blood vessels navigate to their targets. Thus, in this study, we will examine the guidance effect of FGF10 on the pathway finding of both thalamocortical axons and blood vessels in the developing internal capsule. This study will add understanding in the developmental mechanism of the transmission function of the internal capsule, and provide theoretical bases for the clinical studies of this area.

大脑基底部的内囊是一个富含血管和神经纤维的结构。通过此区域的上行及下行神经纤维主要有丘脑皮质束、皮质脑干束和皮质脊髓束等；此区域的主要供血动脉来自于大脑中动脉垂直发出的豆纹动脉。大脑基底部是机体重要的信息传递中心，当此区域受损时，会出现典型的"三偏征"。新近的研究表明，经典轴突导向家族ephrins、slits、semaphorins及netrins不仅调节着轴突的路径选择，还能帮助新生血管到达它们的目的地。另外，有报道指出，组织形态发生分子(morphogens)中的纤维母细胞生长因子(Fibroblast growth factors,FGFs)家族具有相同的功能：对轴突和新生血管同时起着导向作用。在本研究中,我们将检测来自大脑基底部的FGF10对发育中的内囊丘脑皮质轴突和新生血管的化学导向作用。该研究有助于阐述内囊信息传递功能形成的机理，为此区域的临床实践性研究提供理论基础。

丘脑皮质轴突（TCAs）通过复杂的轴突导向机制将外周感觉信息传递到新皮质。腹侧丘脑和大脑腹侧内囊是TCAs经过的两个主要路标。研究表明，组织形态发生分子(morphogens)中的纤维母细胞生长因子(Fibroblast growth factors, FGFs)家族对轴突和新生血管同时起着导向作用。在本研究中,我们将检测来自腹侧丘脑和大脑腹侧内囊的FGF10 对发育中的丘脑皮质轴突和新生血管的化学导向作用。以鸡胚为模型，我们发现FGF10对TCAs导向具有浓度依赖性。在较低浓度下，FGF10吸引TCAs，而在较高浓度下，FGF10排斥TCAs。同时，通过研究FGF10对鸡胚尿囊膜血管生长的影响、以及FGF10对血管内皮细胞血管形成面积的影响，证实FGF10能促进新生血管的生长。