Acute cortical stroke alters neural activity in the subthalamic nucleus, which correlates with motor disability in rats

Abstract

ObjectivesWe aimed to investigate the impact of acute cortical stroke (ACS) on neural activity in subthalamic nucleus (STN). We then examined the correlation between changes in STN activity and motor disability. MethodsForty-four Sprague-Dawley rats were used. While rats were anesthetized, we inserted electrodes in STN and induced an ACS by creating photothrombotic lesion in ipsilateral motor cortex. Local field potentials were recorded before and after ACS. The motor behavior was assessed before and after ACS using single pellet reaching task. ResultsRats experienced significant motor disability after ACS. STN firing rate significantly decreased after ACS. Additionally, delta (0.5-4 Hz) and gamma (50-140 Hz) power significantly decreased after ACS. Furthermore, the decrease in delta mean power correlated with decreases in success rate (r =0.77, p =0.009) and first try success rate (r =0.69, p =0.028). The decreases in gamma mean power (r =0.68, p =0.029) and gamma peak power (r =0.74, p =0.015) correlated with the decrease in success rate. The decrease in gamma power significantly correlated with the decreased STN firing rate. However, decreased delta power exhibited no correlation with decreased gamma power. InterpretationACS causes abnormal STN activity, which correlated with motor disability. Post-stroke STN inhibition may partially compensate for ACS. However, it could also lead to pathological consequences. This STN abnormal activity may serve as a biomarker for motor disability severity after ACS. Furthermore, our findings may provide a possibility for developing neuromodulation strategies, allowing to mitigate post-stroke motor disability through modulating abnormal STN activity.