Hippocampal adult neurogenesis: Its regulation and potential role in spatial learning and memory

- Summarize the data from both laboratory and field studies on adult neurogenesis.
- Discuss the various factors influencing hippocampal adult neurogenesis.
- Review the link between hippocampal adult neurogenesis and spatial learning and memory.
- Highlight the importance of studying natural populations.

Adult neurogenesis, defined here as progenitor cell division generating functionally integrated neurons in the adult brain, occurs within the hippocampus of numerous mammalian species including humans. The present review details various endogenous (e.g., neurotransmitters) and environmental (e.g., physical exercise) factors that have been shown to influence hippocampal adult neurogenesis. In addition, the potential involvement of adult-generated neurons in naturally-occurring spatial learning behavior is discussed by summarizing the literature focusing on traditional animal models (e.g., rats and mice), non-traditional animal models (e.g., tree shrews), as well as natural populations (e.g., chickadees and Siberian chipmunk).