title: The network of causal interactions for beta oscillations in the pedunculopontine nucleus, primary motor cortex, and subthalamic nucleus of walking parkinsonian rats.
abstract: Oscillatory activity has been well-studied in many structures within cortico-basal ganglia circuits, but it is not well understood within the pedunculopontine nucleus (PPN), which was recently introduced as a potential target for the treatment of gait and postural impairments in advanced stages of Parkinson's disease (PD). To investigate oscillatory activity in the PPN and its relationship with oscillatory activity in cortico-basal ganglia circuits, we simultaneously recorded local field potentials in the PPN, primary motor cortex (M1), and subthalamic nucleus (STN) of 6-hydroxydopamine (6-OHDA)-induced hemiparkinsonian rats during resting and walking. After analysis of power spectral density, coherence, and partial Granger causality, three major findings emerged: 1) after 6-OHDA lesions, beta band oscillations were enhanced in all three regions during walking; 2) the direction of information flow for beta oscillations among the three structures was STN→M1, STN→PPN, and PPN→M1; 3) after the treatment of levodopa, beta activity in the three regions was reduced significantly and the flow of beta band was also abrogated. Our results suggest that beta activity in the PPN is transmitted from the basal ganglia and probably comes from the STN, and the STN plays a dominant role in the network of causal interactions for beta activity. Thus, the STN may be a potential source of aberrant beta band oscillations in PD. Levodopa can inhibit beta activity in the PPN of parkinsonian rats but cannot relieve parkinsonian patients' axial symptoms clinically. Therefore, beta oscillations may not be the major cause of axial symptoms.
authors.affiliation: The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.affiliation: The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
authors.forename: Ming
authors.initials: M
authors.lastname: Zhou
authors.affiliation: The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
authors.forename: Peng
authors.initials: P
authors.lastname: Wen
authors.affiliation: The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
authors.forename: Qiang
authors.initials: Q
authors.lastname: Wang
authors.affiliation: The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
authors.forename: Yong
authors.initials: Y
authors.lastname: Yang
authors.affiliation: The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
authors.forename: Hu
authors.initials: H
authors.lastname: Xiao
authors.affiliation: The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China.
authors.forename: Zhengyuan
authors.initials: Z
authors.lastname: Xie
authors.affiliation: Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou 510515, China.
authors.forename: Xing
authors.initials: X
authors.lastname: Li
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Ning
authors.initials: N
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Jinyan
authors.initials: J
authors.lastname: Wang
authors.affiliation: Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing 100101, China.
authors.forename: Fei
authors.initials: F
authors.lastname: Luo
authors.affiliation: Neuroscience Research Institute of North Carolina, Winston-Salem, NC, USA.
authors.forename: Jingyu
authors.initials: J
authors.lastname: Chang
authors.affiliation: The National Key Clinic Specialty, The Engineering Technology Research Center of Education Ministry of China, Guangdong Provincial Key Laboratory on Brain Function Repair and Regeneration, Department of Neurosurgery, Zhujiang Hospital, Southern Medical University, Guangzhou 510282, China. Electronic address: wzhang@vip.126.com.
authors.forename: Wangming
authors.initials: W
authors.lastname: Zhang
mesh_terms: D000818:Animals; D000978:Antiparkinson Agents / Q000494:pharmacology / Q000627:therapeutic use; D001611:Beta Rhythm / Q000502:physiology*; D004195:Disease Models, Animal; D007980:Levodopa / Q000494:pharmacology / Q000627:therapeutic use; D008297:Male; D009044:Motor Cortex / Q000503:physiopathology*; D016627:Oxidopamine / Q000633:toxicity; D010300:Parkinson Disease / Q000188:drug therapy / Q000209:etiology / Q000473:pathology* / Q000503:physiopathology; D045042:Pedunculopontine Tegmental Nucleus / Q000503:physiopathology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013057:Spectrum Analysis; D020531:Subthalamic Nucleus / Q000503:physiopathology*; D014446:Tyrosine 3-Monooxygenase / Q000378:metabolism; D016138:Walking / Q000502:physiology*
chemical_list: D000978:Antiparkinson Agents; D007980:Levodopa; D016627:Oxidopamine; D014446:Tyrosine 3-Monooxygenase
keywords: Beta band oscillations; Local field potentials; Parkinson's disease; Parkinsonian rats; Pedunculopontine nucleus; Primary motor cortex; Subthalamic nucleus