title: Age-related decline in the responsiveness of motor cortex to plastic forces reverses with levodopa or cerebellar stimulation.
abstract: The plasticity of motor cortex is integral for motor memory and skills acquisition but it declines with aging. Forty healthy volunteers, across 6 decades, were tested to examine the (a) age-dependency of motor cortex responsiveness to plasticity induction, as measured from the response to paired associative stimulation (PAS) and the (b) effect of aging on the cerebellar modulation of motor cortex response to PAS. We examined if reduced dopaminergic transmission was involved in the age-related decline of response to PAS by retesting 10 of the older subjects after a single dose of levodopa. There was a substantial decline in the motor cortex response to PAS with aging, which was restored by levodopa in the older subjects. The cerebellar modulation of motor cortex response to PAS was less vulnerable to aging and a single session of cerebellar inhibition reinstated the cortical responsiveness in older subjects. Both levodopa and cerebellar inhibition can be tested for their ability to enhance motor skills acquisition and motor performance in the elderly individuals.
authors.affiliation: Comprehensive Care Centre for Movement Disorders, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India. Electronic address: asha@sctimst.ac.in.
authors.forename: Asha
authors.initials: A
authors.lastname: Kishore
authors.affiliation: Centre de Recherche de la Institut du Cerveau et de la Moelle épinière (CRICM), INSERM U1127, CNRS UMR 7225, Université Pierre et Marie Curie-Paris 6 UMR_S975, Paris, France; Centre de Neuroimagerie de Recherche (CENIR), de la Institut du Cerveau et de la Moelle epiniere (ICM), Paris, France.
authors.forename: Traian
authors.initials: T
authors.lastname: Popa
authors.affiliation: Comprehensive Care Centre for Movement Disorders, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India.
authors.forename: Praveen
authors.initials: P
authors.lastname: James
authors.affiliation: Centre de Neuroimagerie de Recherche (CENIR), de la Institut du Cerveau et de la Moelle epiniere (ICM), Paris, France; CNRS, Centre MEG-EEG, UMR 7225, Paris, France.
authors.forename: Lydia
authors.initials: L
authors.lastname: Yahia-Cherif
authors.affiliation: Comprehensive Care Centre for Movement Disorders, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India.
authors.forename: Febina
authors.initials: F
authors.lastname: Backer
authors.affiliation: Comprehensive Care Centre for Movement Disorders, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India.
authors.forename: Lijo
authors.initials: L
authors.lastname: Varughese Chacko
authors.affiliation: Comprehensive Care Centre for Movement Disorders, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India.
authors.forename: Preetha
authors.initials: P
authors.lastname: Govind
authors.affiliation: Comprehensive Care Centre for Movement Disorders, Department of Neurology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Thiruvananthapuram, Kerala, India.
authors.forename: Salini
authors.initials: S
authors.lastname: Pradeep
authors.affiliation: Centre de Recherche de la Institut du Cerveau et de la Moelle épinière (CRICM), INSERM U1127, CNRS UMR 7225, Université Pierre et Marie Curie-Paris 6 UMR_S975, Paris, France.
authors.forename: Sabine
authors.initials: S
authors.lastname: Meunier
mesh_terms: D000328:Adult; D000368:Aged; D000375:Aging / Q000502:physiology*; D002531:Cerebellum / Q000502:physiology*; D004298:Dopamine / Q000502:physiology; D005071:Evoked Potentials / Q000502:physiology; D005260:Female; D006801:Humans; D007980:Levodopa / Q000494:pharmacology*; D008297:Male; D008875:Middle Aged; D009044:Motor Cortex / Q000502:physiology* / Q000503:physiopathology*; D009048:Motor Skills; D009473:Neuronal Plasticity / Q000502:physiology*; D011597:Psychomotor Performance; D009435:Synaptic Transmission / Q000187:drug effects; D065908:Transcranial Direct Current Stimulation; D055815:Young Adult
chemical_list: D007980:Levodopa; D004298:Dopamine
keywords: Aging; Cerebellum; Levodopa; Motor cortex; Plasticity