title: The Pedunculopontine Tegmental Nucleus as a Motor and Cognitive Interface between the Cerebellum and Basal Ganglia.
abstract: As an important component of ascending activating systems, brainstem cholinergic neurons in the pedunculopontine tegmental nucleus (PPTg) are involved in the regulation of motor control (locomotion, posture and gaze) and cognitive processes (attention, learning and memory). The PPTg is highly interconnected with several regions of the basal ganglia, and one of its key functions is to regulate and relay activity from the basal ganglia. Together, they have been implicated in the motor control system (such as voluntary movement initiation or inhibition), and modulate aspects of executive function (such as motivation). In addition to its intimate connection with the basal ganglia, projections from the PPTg to the cerebellum have been recently reported to synaptically activate the deep cerebellar nuclei. Classically, the cerebellum and basal ganglia were regarded as forming separated anatomical loops that play a distinct functional role in motor and cognitive behavioral control. Here, we suggest that the PPTg may also act as an interface device between the basal ganglia and cerebellum. As such, part of the therapeutic effect of PPTg deep brain stimulation (DBS) to relieve gait freezing and postural instability in advanced Parkinson's disease (PD) patients might also involve modulation of the cerebellum. We review the anatomical position and role of the PPTg in the pathway of basal ganglia and cerebellum in relation to motor control, cognitive function and PD.
authors.affiliation: Laboratories for Neuroscience Visual Neuroscience Group, Graduate School of Frontier Biosciences, Osaka UniversityOsaka, Japan; Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology and Osaka UniversityOsaka, Japan.
authors.forename: Fumika
authors.initials: F
authors.lastname: Mori
authors.affiliation: Laboratories for Neuroscience Visual Neuroscience Group, Graduate School of Frontier Biosciences, Osaka UniversityOsaka, Japan; Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology and Osaka UniversityOsaka, Japan.
authors.forename: Ken-Ichi
authors.initials: KI
authors.lastname: Okada
authors.affiliation: Bio-Dynamics Group, Department of Mechanical Science and Bioengineering, Graduate School of Engineering Science, Osaka University Osaka, Japan.
authors.forename: Taishin
authors.initials: T
authors.lastname: Nomura
authors.affiliation: Laboratories for Neuroscience Visual Neuroscience Group, Graduate School of Frontier Biosciences, Osaka UniversityOsaka, Japan; Center for Information and Neural Networks (CiNet), National Institute of Information and Communications Technology and Osaka UniversityOsaka, Japan; Research Center for Behavioral Economics, Osaka UniversityOsaka, Japan.
authors.forename: Yasushi
authors.initials: Y
authors.lastname: Kobayashi
keywords: Parkinson’s disease; basal ganglia; cerebellum; deep brain stimulation; pedunculopontine tegmental nucleus