Skilled Behaviour and Bilateral Motor Map Expression

Abstract

Multiple seizures cause changes to both cortical movement representations (motor maps) and behavioural impairment. The contribution of seizures to motor map alterations and impaired skilled forelimb movement was studied using the electrical kindling model and short-duration intracortical microstimulation (SD-ICMS). Forelimb motor map movements changed considerably from contralateral in sham-kindled rats to ipsilateral and bilateral in rats kindled for over 5 sessions. Furthermore, bilateral movement representations were related to impairments in skilled forelimb subcomponents. Finally, skilled forelimb impairment was also related to the number of bilateral seizures experienced as well as the duration of bilateral seizures. Next, the role of the ipsilateral hemisphere in bilateral movement representations was examined using SD-ICMS and reversible cooling inactivation. Bilateral representations were produced using electrical kindling as well as pharmacological HCN channel blocker ZD7288. Inactivating the cortex ipsilateral to the skilled forelimb completely eliminated ipsilateral and bilateral movement, indicating its role in bilateral movement representations.