Skip to main content Accessibility help

We use cookies to distinguish you from other users and to provide you with a better experience on our websites. Close this message to accept cookies or find out how to manage your cookie settings.

Close cookie message
×
  1. Home
  2. Search

Refine search

Refine search

Access:
Content type:
Publication date:
Apply   From and To filters
Subject: Show more
Journals Show more
Publishers: Show more
Societies Show more
Series: Show more
Collections: Show more

Actions for selected content:

Select all | Deselect all
  • View selected items
  • Export citations
  • Download PDF (zip)
  • Save to Kindle
  • Save to Dropbox
  • Save to Google Drive

Save Search

You can save your searches here and later view and run them again in "My saved searches".

Please provide a title, maximum of 40 characters.
Cancel
×

2 results

  • Chapter 11 - Changes in Motor Programming with Aging

  • Edited by Kenneth M. Heilman, University of Florida, Stephen E. Nadeau, University of Florida
  • Book:
    Cognitive Changes and the Aging Brain
    Published online:
    30 November 2019
    Print publication:
    05 December 2019, pp 153-167

  • Summary

    The human brain’s motor system, including the motor cortex and corticospinal system, the premotor cortex, basal ganglia, and cerebellum, together with input from sensory and polymodal association cortex, can program almost an infinite number of actions. Therefore, to successfully interact with the environment and ourselves we need the guidance provided by motor programs. There are two major forms of programs, action-intentional (the “when” system) and motor-praxic (the “how” system). The action-intentional system programs when to initiate an action, persist at an action, and terminate an action, or when not to act. The motor-praxic system programs the postures and joint movements required for correct interactions, as well as the speed, force, and sequence of these actions. This chapter describes how different elements of these two major forms of motor programs change with aging as well as the influence of aging on motor learning. The mechanisms that induce the aging-related changes in motor programming, motor skill learning, and motor performance are not fully known; however, in this chapter we discuss the various types of aging-related changes, their possible mechanisms, and how some of the changes can be limited and/or treated.

  • Functional anatomy of movement disorders

  • A. R. CROSSMAN
  • Journal:
    The Journal of Anatomy / Volume 196 / Issue 4 / May 2000
    Published online by Cambridge University Press:
    01 May 2000, pp. 519-525
    Print publication:
    May 2000

  • Models of basal ganglia function are described which encapsulate the principal pathophysiological mechanisms underlying parkinsonian akinesia on the one hand and abnormal involuntary movement disorders (dyskinesias) on the other. In Parkinson's disease, degeneration of the nigrostriatal dopamine system leads to overactivity of the ‘indirect’ striatopallidal projection to the lateral (external) segment of the globus pallidus. This causes inhibition of lateral pallidal neurons, which in turn project to the subthalamic nucleus. Disinhibition of the subthalamic nucleus leads to abnormal subthalamic overactivity and, as a consequence, overactivity of medial (internal) pallidal output neurons. Dyskinesias, such as are observed in Huntington's disease, levodopa-induced dyskinesia and ballism, share mechanistic features in common and are associated with decreased neuronal activity in both the subthalamic nucleus and the medial globus pallidus.