The effects of paired associative stimulation on sensorimotor function and the expression of MAP-2 and GAP-43 after focal cerebral ischemia and reperfasion / 中华物理医学与康复杂志

ABSTRACT

Objective To observe the effect of paired associative stimulation ( PAS) on the recovery of sensorimotor function and to explore the mechanism in terms of neural plasticity. Methods Ninety male adult Sprague-Dawley rats were randomly divided into a sham operation group (Sham group), a model group (Model group) and a paired associative stimulation group ( PAS group) , each of 30. Each group was then subdivided into 7-, 14-and 28-day subgroups with 10 rats in each. A model of focal cerebral ischemia and reperfusion was estab-lished using the Longa suture method in the Model and PAS groups. The rats in the Sham group underwent the same surgical procedure except for the occlusion of the middle cerebral artery. The rats received 30 minutes of paired pe-ripheral nerve stimulation and transcranial magnetic stimulation comprising 90 pairs at 0.05 Hz beginning 24 h after the occlusion. The impulse wave width of the peripheral nerve stimulation was 200 μs and the intensity was 6 mA. The intensity of the transcranial magnetic stimulation was 120％ of the resting motor threshold. The other two groups weren't given any intervention. Neurological function was tested using Garcia scores on the 1st, 7th, 14th and 28th day after surgery. The rats were then sacrificed and the expression of MAP-2 and GAP-43 in the ischemic penumbra were detected using western blotting and immunohistochemistry. Results No neurological dysfunction was ob-served in the Sham group at any time. Compared with the Sham group at the same time points, the average Garcia scores of the Model and PAS groups were significantly lower (P≤0.05). However, the average Garcia scores on the 7th, 14th and 28th day were significantly higher in the PAS group compared with the Model group at the same time points ( P≤0.05) . The average Garcia scores of the Model and PAS groups on the 28th day after surgery were significantly higher than those on the 1st day (P≤0.05), but only the PAS group's average Garcia score on the 28th day was significantly higher than that on the 7th day. Compared with the Sham group at the same time points, the expression of MAP-2 and GAP-43 protein in the Model and PAS groups was significantly higher, but with that of the Model group significantly lower than that of the PAS group ( all P≤0.05) . The protein expression of MAP-2 and GAP-43 protein in the PAS group on the 14th day was significantly higher than on the 7th and 28th day ( P≤0.05 for both) . Conclusions PAS can promote the recovery of sensorimotor function after cerebral thrombosis, at least in rats. That may be due to its promoting the expression of the neuroplasticity-associated proteins MAP-2 and GAP-43 in the ischemic penumbra.