The researchers boosted the number of neurons in the hippocampus, an area of the brain involved in memory and mood, and tested the mice in both learning and mood-related tasks, looking for changes in behavior.
They found specific effects on learning tasks that involve a process called pattern separation, which is the ability to distinguish between similar places, events, and experiences. Pattern separation is important for learning, since it helps determine whether something is familiar or novel.
Pattern separation may also be important for anxiety disorders, including post traumatic stress disorder (PTSD) and panic disorder. People with PTSD, say the researchers, have a more generalized fear response, so that when they are placed in a situation that reminds them of even one aspect of their trauma, they frequently have a full fear response.
The researchers say that the genetic strategy used to stimulate neurogenesis in their experiments can be mimicked pharmacologically, potentially leading to the development of new drugs to reverse pattern separation deficits and improve cognition and mood.
Ref.: René Hen et al., Increasing adult hippocampal neurogenesis is sufficient to improve pattern separation, April 3 online edition, Nature