TY - JOUR T1 - Sleep-State Dependent Alterations in Brain Functional Connectivity under Urethane Anesthesia in a Rat Model of Early-Stage Parkinson’s Disease JF - eneuro JO - eNeuro DO - 10.1523/ENEURO.0456-18.2019 VL - 6 IS - 1 SP - ENEURO.0456-18.2019 AU - Ekaterina Zhurakovskaya AU - Juuso Leikas AU - Tiina Pirttimäki AU - Francesc Casas Mon AU - Mikko Gynther AU - Rubin Aliev AU - Tomi Rantamäki AU - Heikki Tanila AU - Markus M. Forsberg AU - Olli Gröhn AU - Jaakko Paasonen AU - Aaro J. Jalkanen Y1 - 2019/01/01 UR - http://www.eneuro.org/content/6/1/ENEURO.0456-18.2019.abstract N2 - Parkinson’s disease (PD) is characterized by the gradual degeneration of dopaminergic neurons in the substantia nigra, leading to striatal dopamine depletion. A partial unilateral striatal 6-hydroxydopamine (6-OHDA) lesion causes 40–60% dopamine depletion in the lesioned rat striatum, modeling the early stage of PD. In this study, we explored the connectivity between the brain regions in partially 6-OHDA lesioned male Wistar rats under urethane anesthesia using functional magnetic resonance imaging (fMRI) at 5 weeks after the 6-OHDA infusion. Under urethane anesthesia, the brain fluctuates between the two states, resembling rapid eye movement (REM) and non-REM sleep states. We observed clear urethane-induced sleep-like states in 8/19 lesioned animals and 8/18 control animals. 6-OHDA lesioned animals exhibited significantly lower functional connectivity between the brain regions. However, we observed these differences only during the REM-like sleep state, suggesting the involvement of the nigrostriatal dopaminergic pathway in REM sleep regulation. Corticocortical and corticostriatal connections were decreased in both hemispheres, reflecting the global effect of the lesion. Overall, this study describes a promising model to study PD-related sleep disorders in rats using fMRI. ER -