Mechanisms of aluminium neurotoxicity in oxidative stress-induced ...

The basal ganglia
INTRODUCTION
The basal ganglia (BG) constitute mainly five subcortical nuclei located deep in
the hemispheres: the substantia nigra with its pars compacta (SNpc) and pars reticularis
(SNpr), the striatum (caudate nucleus and putamen), the internal and external segments
of globus pallidus (GPi and GPe), and the subthalamic nucleus (STN) (Figure 7). The
BG form a complex network of anatomically and functionally segregated loops
involved in the regulation of emotional and cognitive functions and particularly in the
control of cortically initiated motor activity, which if disturbed leads to some form of
movement disorder.
Figure 7: The basal ganglia (Society for Neuroscience www.sfn.org)
These parallel loops have been functionally subdivided into motor, oculomotor,
limbic, association and orbitofrontal loops (Alexander et al. 1986, Alexander and
Crutcher 1990, Middleton and Strick 2000). The striatum is the primary input structure
of BG as it receives excitatory glutamatergic signals from many areas of the sensory
motor cortex and thalamus, as well as a dense innervation from midbrain DA neurons.
The most abundant striatal neurons are striatonigral and striatopallidal neurons
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