Neurons have long held the spotlight as the central players of the nervous system, but we must remember that we have equal numbers of astrocytes and neurons in the brain. Are these cells only filling up the space and passively nurturing the neurons, or do they also contribute to information transfer and processing? After several years of intense research since the pioneer discovery of astrocytic calcium waves and glutamate release onto neurons in vitro, the neuronal-glial studies have answered many questions thanks to technological advances. However, the definitive in vivo role of astrocytes remains to be addressed. In addition, it is becoming clear that diverse populations of astrocytes coexist with different molecular identities and specialized functions adjusted to their microenvironment, but do they all belong to the umbrella family of astrocytes? One population of astrocytes takes on a new function by displaying both support cell and stem cell characteristics in the neurogenic niches. Here, we define characteristics that classify a cell as an astrocyte under physiological conditions. We will also discuss the well-established and emerging functions of astrocytes with an emphasis on their roles on neuronal activity and as neural stem cells in adult neurogenic zones.

中文翻译：

---

星形胶质细胞漫游。

长期以来，神经元一直是神经系统中枢的焦点，但我们必须记住，大脑中星形胶质细胞和神经元的数量相等。这些细胞是仅填充空间并被动地滋养神经元，还是它们也有助于信息传递和处理？自从在体外首次发现星形细胞钙波和谷氨酸释放到神经元后，经过数年的深入研究，神经胶质研究由于技术的进步回答了许多问题。然而，星形胶质细胞在体内的确定性作用仍有待解决。此外，越来越明显的是，星形胶质细胞的不同群体并存，它们具有不同的分子特性和适应其微环境的专门功能，但是它们都属于星形胶质细胞的伞形科吗？一组星形胶质细胞通过在神经源性壁ches中同时显示支持细胞和干细胞特征来承担新的功能。在这里，我们定义了在生理条件下将细胞分类为星形细胞的特征。我们还将讨论星形胶质细胞已确立和新兴的功能，重点是它们在神经元活动中的作用以及在成人神经源性区域中作为神经干细胞的作用。