Objective: To explore the underlying mechanism of acupuncture on nerve repair by investigating its effect on the differentiation of glial cells and the repair of glial scars.
Methods: Sprague-Dawley rats were randomly allocated to three groups: normal group, model group, and acupuncture group. Acupuncture was applied at Renzhong (GV26), Baihui (GV20), Fengfu (GV16), Yamen (GV15) and Hegu (LI4) within 12 h after TBI modeling with a frequency of one session per day for 4 weeks. Neurobehavioral assessment, hematoxylin and eosin staining, immunofluorescence detection, and magnetic resonance imaging scanning were performed on days 3, 7, 14, and 28 after modeling of traumatic brain injury (TBI).
Results: Acupuncture promoted the proliferation of glial cells and glial scars at an early stage but inhibited the proliferation of glial cells and glial scars at a late stage. Morphological observations and immunofluorescence histochemistry showed that the morphology of the perilesional cortex in the acupuncture group was improved and the number of neurons was increased when compared with the model group. The lesion size of ipsilateral brain parenchyma in the acupuncture group was smaller than in the model group on days 7, 14, and 28 ( < 0.05) after TBI modeling.
Conclusions: Acupuncture might have a bidirectional regulatory effect on glial scar repair after TBI by promoting the proliferation of glial cells and glial scars to limit the injured area and relieve nerve injury during the early stages, and by inhibiting glial scar hyperplasia to benefit the regeneration and repair of neurons and axons and promote neurological function recovery during the later stages.
Keywords: acupuncture; astrocytes; brain injuries, traumatic; gliosis; microglia.