Abstract:

Objective    To investigate the effects and mechanism of Pioglitazone on traumatic brain injury（TBI）-induced deficits of learning memory ability and damages of hippocampus neurons in rats. Methods    Left lobus parietalis damage models were made in 24 SD rats which were randomly divided into four groups: Sham group, Vehicle group, Pio group and Pio +Ant group. Morris water maze was used to observe the changes of their learning memory behavior. On the 15th day the rats were sacrificed to make brain coronal frozen sections. NeuN,OX-42 and GFAP immunohistochemistry were used to stain neuron, microglia and astrocyte, and their numbers in hippocampus CA1,CA2 and CA3 areas were counted. Results    Morris water maze test indicated that compared with the Sham group the learning ability of the Vehicle group dropped significantly which manifested as extension of latency（P<0.01）and distance（P<0.01）; the number of neurons was decreased (P<0.01) and NeuN stain was light; the numbers of microglias(P<0.01) and astrocytes (P<0.01) were increased. The Pio group had shorter latency and distance than the Vehicle group（both P<0.05）; the number of survival neurons was increased(P<0.05) and the expression of NeuN was strengthened; thenumbers of microglias(P<0.05) and astrocytes were decreased(P<0.05). Conclusion    According to PPARγ pathway Pioglitazone can alleviate the TBI-induced inflammatory reaction in hippocampus and plays an important role in neuron protection and learning memory ability.

Key words: Brain injuries;  Maze learning; Inflammation; Neurons; Peroxisome-proliferator-activated receptor-γ