Adult Born Dentate Granule Cell Mediated Upregulation of Feedback Inhibition in a Mouse Model of Traumatic Brain Injury

Traumatic brain injury (TBI) can lead to post-traumatic epilepsy (PTE), potentially due to changes in the brain's structure and function. This study investigates how new brain cells, called dentate granule cells (DGCs), formed after TBI affect brain activity and the balance between excitation and inhibition in the dentate gyrus. The researchers used a mouse model of TBI to examine DGCs born at different times relative to the injury. They specifically looked at how these DGCs influence feedback inhibition, a process where certain brain cells control the activity of others to prevent over-excitation, which can lead to seizures. The findings suggest that DGCs born just before the injury play a crucial role in increasing feedback inhibition after TBI. This increased inhibition may be a way the brain tries to compensate for the injury, but it could also contribute to other problems like cognitive dysfunction.

• 1
  Activation of DGCs born before CCI increased feedback inhibition in mature DGCs and excitation in parvalbumin-expressing basket cells (PVBCs) compared to sham controls.
• 2
  This upregulated feedback inhibition was less prominent in DGCs born early in life or after CCI.
• 3
  Adult born DGCs did not contribute significantly to recurrent excitation of DGCs that develops after CCI injury.