Alterations in the functional organization of motor cortex and interictal motor deficits are observed in people with epilepsy. While seizures in the rat lead to more cortical area devoted to simple cortical forelimb movement representations (motor maps) assessed using short-duration intracortical microstimulation (ICMS), the effect of seizures on complex movements derived with long-duration ICMS is unknown. Further, the relationship between motor map expression and motor impairment is not well understood. We used long-duration ICMS in the rat to test the hypothesis that repeated seizure activity (cortical kindling) increases the extent of overlapping cortical representation where multiple forelimb movements are evoked to stimulation. Cortical kindling (n = 7) significantly expanded (100%) forelimb motor maps characterized by a proportional increase in both complex and simple movement representation areas, and significantly increased (285%) overlapping forelimb representation compared to sham-kindled controls (n = 5). In a second experiment, motor maps were derived with long-duration ICMS under acute cortical application of bicuculline (n = 6) to reduce intracortical inhibition or saline control (n = 10). Bicuculline also significantly expanded forelimb motor maps (108%) but without increasing representational overlap. Moreover, expanded map areas in bicuculline rats evoked qualitatively distinct forelimb movements to long-duration, but not short-duration (n = 5), ICMS that were truncated. Our evidence indicates that motor map expansion following repeated experimental seizures is associated with reduced segregation between cortical movement representations that is not entirely due to reduced cortical inhibition but may contribute to interictal motor deficits in some individuals with epilepsy.

在癫痫患者中观察到运动皮层的功能组织和间质运动缺陷的改变。虽然大鼠的癫痫发作导致更多的皮质区域专门用于使用短期皮质内微刺激（ICMS）评估的简单皮质前肢运动表征（运动图），但癫痫发作对长期ICMS引起的复杂运动的影响尚不清楚。此外，对运动图表达和运动障碍之间的关系还没有很好的理解。我们在大鼠中使用了长期的ICMS来检验以下假设：反复的癫痫发作活动（皮层点燃）会增加皮质皮层重叠的程度，在皮层皮层中多处前肢运动被刺激。皮质火种（ñ = 7）显着扩展（100％）的前肢运动图，其特征在于复杂和简单的运动表示区域都成比例地增加，并且与假假对照相比（n  = 5）显着增加（285％）重叠的前肢表示。在第二个实验中，在长期应用双小分子的急性皮层注射（n  = 6）以减少皮层内抑制或盐水控制（n  = 10）的情况下，使用长期ICMS得出了运动图。Bicuculline还显着扩展了前肢运动图（108％），但没有增加代表重叠。此外，双眼大鼠扩大的图谱区域引起了长时而非短时的定性独特的前肢运动（n = 5），被截断的ICMS。我们的证据表明，反复实验性癫痫发作后的运动图扩展与皮质运动表现之间的分离减少有关，这并不完全是由于皮质抑制作用的降低，而是可能导致某些癫痫患者的发作间期运动障碍。