Basal Ganglia: The Centers of Movement

Silvia Helena Cardoso, PhD



Horizontal section from the Visible Human

The basal ganglia refer to a group of closely connected structures including the striatum (the caudate and the putamen), the globus pallidus, the substantia nigra and the subthalamic nucleus.

It seems to be generally agreed that the basal ganglia have something to do with the creation and execution of motor plans. Just watch a person with a typical basal ganglion affliction, such as Parkinson's disease, characterized by difficulty in starting or stopping the walking sequence, and realize how profundly these nuclei are involved in daily life.

In addition to their role in control of movement and posture, it now appears that the basal ganglia also play a more complex (cognitive) aspects of behavior and may be involved in limbic functions.

They are responsible not only for the integration of motor activity but probably also for the programming, beginning and termination of such activity.

There are other definitions of the term basal ganglia: the archistriatum, the paleostriatum, and the neostriatum.

Archistriatum
consists of the Amygdala
Paleostriatum
(paleo = ancient ) or "pallidum"
is the forerunner of the mammalian corpus striatum
consists of the Globus pallidus
Neostriatum
(neo = new) This is a phylogenetically new component
of the brain. It appears in the reptilian brain and forms
the largest part of the corpus striatum in mammals.
consists of the Caudate nucleus
Putamen
(together called
corpus striatum)

Neurons in caudate and putamen are basically
of two basic types, projection neurons and
interneuons.They contain the inhibitory neurotransmitter gamma-aminobutyric acid (GABA). Other neurons have
have interneuronal function. They use the transmitter
acetylcholine (Ach) and are extitatory. All neurons
also contain various neuropeptides (enkephalin,
substance P, neuropeptide Y) that are co-released with the neurotransmitters.




The Components the Basal Ganglia

Connections of the Basal Ganglia

PET Images in Parkinson's Disease


Author: Dr. Silvia Helena Cardoso, PhD. Psychobiologist, master and doctor in Sciences by the University of São Paulo and post doctoral fellowship by the University of California, Los Angeles. Invited Professor and Associate Researcher of the Center for Biomedical Informatics, State University of Campinas (Unicamp), Brazil.

Center for Biomedical Informatics
State University of Campinas, Brazil

Copyright 1997 State University of Campinas