Effects of trigeminal nerve electrical stimulation on hippocampal neuronal apoptosis and GLT-1 expression in rats with global cerebral ischemia.

OBJECTIVE

To investigate the effects of trigeminal nerve stimulation (TNS) on hippocampal neuronal apoptosis and the expression of glutamate transporter 1 (GLT-1) in rats with global cerebral ischemia.

METHODS

Forty SD rats were randomly assigned to four groups: the Sham group, Cerebral Ischemic Injury (CI) group, Trigeminal Nerve Stimulation (TNS) group, and Caspase-3-specific inhibitor Z-DEVD-FMK (FMK) group. A global cerebral ischemia-hypoxia model was established using the four-vessel occlusion method. The TNS and FMK groups received implantation of trigeminal ganglion stimulation electrodes, with the first stimulation administered 30 min after successful model establishment, followed by stimulation every 6 h for a total of four sessions. After 24 h, the rats were euthanized, the hippocampal CA1 region was rapidly dissected, and TUNEL staining was performed. Additionally, Western blot analysis was conducted to evaluate the protein expression of GLT-1, Bax, Bcl-2, and Caspase-3.

RESULTS

The apoptosis index was significantly higher in the CI, TNS, and FMK groups. However, compared to the CI group, the TNS group exhibited a significant reduction in the apoptosis index (P < 0.05). Additionally, compared to the Sham group, the TNS group showed downregulation of Bax and Caspase-3, and upregulation of Bcl-2 and GLT-1 (P < 0.05).

CONCLUSION

The arousal-promoting effect of TNS may be linked to the upregulation of GLT-1 expression through the Bax/Bcl-2/Caspase-3 signalling pathway, resulting in reduced neuronal apoptosis in the hippocampal CA1 region.