Chapter 18 - Modulation of Movement by the Basal Ganglia Flashcards
What is the basal ganglia?
The term basal ganglia refers to a large and functionally diverse set of nuclei that lies deep within the cerebral hemispheres.
The motor nuclei of the basal ganglia are divided into several functionally distinct groups. The two largest of these groups are..
- Corpus striatum (caudate, putamen)
2. Pallidum (globus pallidus, substantia nigra pars reticulata)
The two principle nuclei of the corpus striatum, the largest basal ganglia motor nuclei group, are …
- Caudate
2. Putamen
What gives the corpus striatum (caudate, putamen) its name?
The name corpus striatium, which means “striped body”, reflects the fact that the caudate and the dorsal part of the putamen are joined by slender bridges of gray matter that extend through the internal capsule and confer a striped appearance in parasaggital sections through this area.
The two subdivisions of the corpus striatum (caudate and putamen) comprise the …. zone of the basal ganglia.
The two subdivisions of the corpus striatum (caudate and putamen) comprise the input zone of the basal ganglia.
The two subdivisions of the corpus striatum (caudate and putamen) comprise the input zone of the basal ganglia. Where does the input come from?
The cortex.
The destinations of the incoming axons from the cerebral cortex to the basal ganglia are the dendrites of a class of cells in …… called ….
The destinations of the incoming axons from the cerebral cortex to the basal ganglia are the dendrites of a class of cells in the corpus striatum called medium spiny neurons.
The medium spiny neurons of the basal ganglia are in which subsection of the ganglia?
They are in the caudate and putamen.
The mediun spiny neurons of the caudate and putamen have axons that converge on neurons in …
the pallidum (globus pallidus, substantia nigra pars reticulata).
The globus pallidus and substantia nigra pars reticulata are the main sources of …. from the basal ganglia complex.
The globus pallidus and substantia nigra pars reticulata are the main sources of output from the basal ganglia complex.
What is the corticostriatal pathway?
Nearly all regions of the cerebral cortex project directly to the corpus striatum. All of these projections are referred to collectively as the corticostriatal pathway.
Both parts of the corpus striatum (putamen and caudate) receieve innervation from the cortex. Is there a difference between what kind of information they receive?
We don’t really know, but they do have different cortical sources of information.
Putamen: Receives input from the primary and secondary somantic sensory contices in the parietal lobe, and higher order visual cortices in the occipital and temporal lobes, the premotor and motor cortices int he frontal lobe, and the auditory association areas in the temporal lobe.
Caudate: receives cortical projections primarily from multimodel association cortices and motor areas in the frontal lobe than control eye movements.
The medium spiny neurons’ firing is associated with …
Their firing is associated with the occurence a movement. Extracellular recordings show that these neurons typically increase their rate of discharge before an impending movement.
What has made some researchers suggest that the activity of neurons in the corpus striatum may encode the decision to move rather than the actual movement?
Becuse the discharges of some striatal neurons vary according to the location in space of the destination of a movement, rather than the starting position of the limb relative to the destination.
The efferent cells of the globus pallidus and substantia nigra pars reticulata use what neurotransmitter?
GABA. Therefore they are inhibitory.
