Rebound Excitability Mediates Motor Abnormalities in Parkinson’s Disease |
Jeongjin Kim1, Daesoo Kim1,* |
1Department of Biological Sciences, KAIST, 34141 Daejeon, Republic of Korea, 2Center for Neuroscience, KIST, Seoul 02792, Republic of Korea |
Abstract
Parkinson’s disease (PD) is a debilitating disorder resulting from loss of dopamine neurons. In dopamine deficient state, the basal ganglia increases inhibitory synaptic outputs to the thalamus. This increased inhibition by the basal ganglia output is known to reduce firing rate of thalamic neurons that relay motor signals to the motor cortex. This ‘rate model’ suggests that the reduced excitability of thalamic neurons is the key for inducing motor abnormalities in PD patients. We reveal that in response to inhibition, thalamic neurons generate rebound firing at the end of inhibition. This rebound firing increases motor cortical activity and induces muscular responses that triggers Parkinsonian motor dysfunction. Genetic and optogenetic intervention of the rebound firing prevent motor dysfunction in a mouse model of PD. Our results suggest that inhibitory synaptic mechanism mediates motor dysfunction by generating rebound excitability in the thalamocortical pathway.
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Abstract, Accepted Manuscript(in press) [Submitted on January 11, 2018, Accepted on January 11, 2018] |
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