Research Reports - The accumulation of brain injury leads to severe neuropathological and neurobehavioral changes after repetitive mild traumatic brain injury
Brain Res. 2016 Dec 3. pii: S0006-8993(16)30802-2. doi:
10.1016/j.brainres.2016.11.028. [Epub ahead of print]
Gao H(1), Han Z(2), Bai R(2), Huang S(1), Ge X(1), Chen F(1), Lei P(3).
Traumatic brain injury (TBI) is a major public health problem with long-term
neurobehavioral sequela. The evidences have revealed that TBI is a risk factor
for later development of neurodegenerative disease and both the single and
repetitive brain injury can lead to the neurodegeneration. But whether the
effects of accumulation play an important role in the neurodegenerative disease
is still unknown. We utilized the Sprague Dawley (SD) rats to develop the animal
models of repetitive mild TBI and single mild TBI in order to detect the
neurobehavioral changes. The results of neurobehavioral test revealed that the
repetitive mild TBI led to more severe behavioral injuries than the single TBI.
There were more activated microglia cells and astrocytes in the repetitive mild
TBI group than the single TBI group. In consistent with this, the levels of TNF-α
and IL-6 were higher and the expression of IL-10 was lower in the repetitive mild
TBI group compared with the single TBI group. The expression of amyloid precursor
protein (APP) increased in the repetitive TBI group detected by ELISA and western
blot. But the levels of total tau (Tau-5) and P-tau (ser202) seem no different
between the two groups in most time point. In conclusion, repetitive mild TBI
could lead to more severe neurobehavioral impairments and the effects of
accumulation may be associated with the increased inflammation in the brain.