Final answer:
Apical progenitor cells can generate neurons and glial cells through signals from growth factors during neural system formation. Neurons and astrocytes can be distinguished using markers such as GFAP in imaging techniques. Glial cells, including astrocytes, provide essential support and modulation of nerve activity.
Step-by-step explanation:
How Apical Progenitor Cells Generate Neurons and Glial Cells
During the process of neurogenesis in vertebrates, apical progenitor cells, which originate from the ectodermal layer, have the potential to generate neurons and glial cells. Specialized signaling molecules, known as growth factors, guide the differentiation of these progenitor cells during the early stages of neural system formation. These growth factors instruct some ectodermal cells to become epidermal cells, while those that do not receive this signal continue to form the neural plate, eventually giving rise to both neurons and various types of glial cells, such as astrocytes and oligodendrocytes.
In the developing neural system, these progenitor cells divide and differentiate in response to growth factors. Neurons and glial cells are distinguished by specific markers, such as glial fibrillary acidic protein (GFAP) which is expressed by astrocytes but not by neurons. A micrograph may showcase newly formed neurons in the rat hippocampus, labeling the dividing cells with BrdU, which incorporates into the DNA during cell replication, appearing in red. Cells that express both BrdU and GFAP indicate actively dividing astrocytes, whereas cells labeled only with BrdU represent actively dividing neurons.
Glia cells such as astrocytes, microglia, oligodendrocytes, and satellite glia play crucial roles in supporting neurons, from providing nutrients to forming myelin sheaths. They also respond to and modulate nerve activity, with recent findings suggesting an active role in synaptic communication.