Final answer:
After a traumatic brain injury, there is typically a decrease in N-acetylaspartate (NAA), which is a marker of neuronal integrity and is used to gauge the extent of neuronal damage.
Step-by-step explanation:
People suffering from traumatic brain injuries (TBIs) often experience a decrease in the level of N-acetylaspartate (NAA) in the brain. NAA is considered a marker of neuronal integrity and is typically found in high concentrations in healthy brains. After a TBI, the decrease in NAA can be used to indicate the extent of neuronal loss or damage. Although TBIs can also affect various neurotransmitter levels, such as dopamine, the specific question about a decrease following a TBI correlates most strongly with NAA levels.
The loss of NAA is considered part of the secondary injury cascade that occurs after the initial traumatic event and is associated with the excitotoxicity that ensues, leading to further neuronal damage.