Scalp Acupuncture Combined with Exercise Induces PI3K/Akt Activation and Improves Synaptic Plasticity in Post-Stroke Spastic Rats.

Effective treatments for post-stroke spasticity (PSS) remain limited, and the mechanism by which scalp acupuncture combined with exercise (SAE) alleviates PSS is not fully understood. This study investigated the effects of SAE in rats with PSS and explored whether SAE regulates synaptic plasticity through the PI3K/Akt pathway. A middle cerebral artery occlusion (MCAO) rat model was established, and rats were randomly assigned to five groups: Blank, Sham, MCAO, SAE, and Baclofen. All interventions were administered for 7 consecutive days. Neurological function, cerebral infarct volume, histopathology, synaptic ultrastructure, and related protein expression were then evaluated. Compared with the MCAO group, SAE improved neurological deficits, reduced muscle hypertonia, decreased infarct volume, alleviated neuronal injury, increased synapse number, and improved synaptic morphology. SAE also upregulated glial cell line-derived neurotrophic factor (GDNF), phosphorylated PI3K (p-PI3K), phosphorylated Akt (p-AKT), and synaptic proteins, including synaptophysin (SYN), postsynaptic density protein 95 (PSD-95), and growth-associated protein 43 (GAP-43). Immunofluorescence staining further suggested enhanced expression of SYN and p-Akt in the motor cortex after SAE treatment. These findings suggest that SAE may be correlated with the activation of PI3K/Akt signaling via upregulation of GDNF, thereby improving synaptic plasticity and alleviating PSS symptoms. This study investigated the effects of SAE in rats with PSS and explored the potential association between SAE intervention, PI3K/Akt pathway activity, and synaptic plasticity.