In Spinal Cord, NGF and TrkA could be detected in the gray matter at embryonic week 6, the expressional range and immunoreactive staining were gradually increased as the developmental process.

• 山羊胎儿脊髓灰质中存在NGF及其受体TrKA，于E6W就可检测到，随胚龄增加，其表达范围及免疫反应着色程度逐渐加大。