Conditional knockout of brain-derived neurotrophic factor in the hippocampus increases death of adult-born immature neurons following traumatic brain injury.

It has been reported that the hippocampus is particularly vulnerable to traumatic brain injury (TBI), the consequence of which results in hippocampal-dependent cognitive impairment. In the previous study we found that adult-born immature neurons in the hippocampal dentate gyrus are the most vulnerable cell type to moderate TBI insult. However, the molecular mechanisms that regulate the survival of adult-born immature neurons in the hippocampus following TBI are still not well understood. Here, we conditionally knocked out brain-derived neurotrophic factor (BDNF) in the hippocampal dentate gyrus and examined the death of adult-born immature neurons following moderate TBI. The results showed that the amount of adult-born immature neuron death in the hippocampal dentate gyrus significantly increased in the BDNF conditional knockout mice. This result suggests that BDNF is involved in regulating the survival of adult-born immature neurons in the hippocampus following TBI, and potentially might be a useful target for preventing the adult-born immature neurons from death following TBI.