My name is Dr. Yoland Smith.
I'm a neuroscientist at the Yerkes
National Primate Research Center
and at the Department of
Neurology of Emory University.
For the past 30 years,
my main research interest
had being devoted
to the understanding
of the anatomical and functional
organization of the basal ganglia
in normal and diseased conditions,
particularly in relation
to Parkinson's disease.
In this presentation, I will give
an overview of our current knowledge
of the thalamic regulation
of striatal function
in normal and Parkinsonian states.
Our current view of the
relationships between the thalamus
and the basal ganglia are shown
on this slide, which illustrates
simplified schematics of the basal
taken from a textbook commonly
used in neuroscience education.
As you can see from this diagram,
the thalamus and the basal ganglia
nuclei are part of functional loops
through which the information flows
from the cerebral cortex to
the striatum, which in primates
comprise the caudate
nucleus in the putamen,
and then to globus pallidus and the
substantia nigra pars reticulata,
which, in turn, send gabaergic
projection to the thalamus.
The thalamus then
transmits this information
the cerebral cortex and so on.
This arrow diagram shows the same
basal ganglia-thalamocortical loop
in a highly schematic fashion.
However, my talk today will
not be focused on this system,
but will rather discuss the
organization of another projection
system that bypasses
the cerebral cortex
and links directly the
thalamus with the striatum--
Although this network
has long been known,
our limited understanding of its
basic anatomical, physiological,
and pathophysiological organization
has significantly hampered advances
in knowledge about the
role of this system
in the functional circuitry
of the basal ganglia
in normal and diseased states.