What is neurogenesis?

Neurogenesis refers specifically to the formation of new neurons from neural stem cells and progenitor cells. This process occurs predominantly during development but can also happen in certain brain regions in adults, particularly in areas like the hippocampus, which is involved in memory and learning. Neurogenesis plays a crucial role in cognitive functions and emotional regulation, contributing to brain plasticity.

The other options pertain to different processes affecting neurons. The loss of existing neurons suggests a reduction in neuronal populations, while degeneration of brain cells typically involves deterioration of function and structure, often associated with conditions like neurodegenerative diseases. Neuron apoptosis refers to programmed cell death, which is a natural process that helps regulate cell populations and remove damaged cells, but it is not the formation of new neurons. Therefore, the correct understanding of neurogenesis is about the creation of new neuronal cells, making it an essential process for brain health and adaptability.