Which cell type is typically unable to regenerate once differentiated?

Neurons are indeed typically unable to regenerate once they have fully differentiated. This lack of regenerative ability is primarily due to the complex structure of neurons and their role in the nervous system. Once neurons have formed and established connections with other neurons, they enter a specialized state without the capability to divide and produce new cells. This characteristic has significant implications for conditions affecting the nervous system, such as neurodegenerative diseases, and explains why injuries to the brain and spinal cord can result in lasting damage.

In contrast, stem cells have the unique ability to differentiate into various cell types and can regenerate and replicate themselves. Skin cells are part of the body's regenerative system and can frequently undergo division to replace lost or damaged cells. White blood cells can be produced in response to pathogens and can regenerate as needed to respond to immune challenges. Therefore, the regenerative capacity varies significantly among these cell types, with neurons being the most notably limited in their ability to regenerate after differentiation.