Organization of the Basal Ganglia

Question 1

Give a general description of the currently understood function of the Basal Ganglia:

Answer 1

Selection of certain motor/cognitive programs given sensory input and suppression of other motor/cognitive programs.

Question 2

List some symptoms or syndromes that could result from some damage to the basal ganglia:

Answer 2

Parkinsons, Chorea (Huntingtons), Athetosis, Ballism.

Question 3

Name the input nuclei of the basal ganglia and the type of information that they process:

Answer 3

Caudate (cognitive), Putamen (sensorimotor), Nucleus Accumbens (limbic)

Question 4

Name the intrinsic nuclei of the basal ganglia:

Answer 4

Subthalamic nucleus, external globus pallidus, substantia nigra pars compacta, Ventral Tegmental area.

Question 5

Name the output nuclei of the basal ganglia:

Answer 5

Ventral Pallidum, Internal Globus Pallidus, Substantia Nigra Pars Reticulata.

Question 6

Name the tracts that terminate in the striatum:

Answer 6

Corticostriatal, Nigrostriatal (from pars compacta), Thalamostriatal (from parafasciculus (to caudate), centromedian (putamen))

Question 7

Neurons in the striatum transmit which type of neurotransmitter? What transmitter types do they receive?

Answer 7

Transmit GABA, substance P (direct pathway), dynorphin (direct), enkephalin (indirect), Receive Dopamine, Glutamate, Substance P.

Question 8

Name the internuclear connections of the basal ganglia and their parts:

Answer 8

Subthalamic Fasciculus (bidirectional connections between external globus pallidus and subthalamic nucleus; subthalamic nucleus to internal globus pallidus and substantia nigra pars reticulata), Dopaminergic Pathway (substantia nigra pars compacta to neostriatum, ventral tegmental area to nucleus accumbens)

Question 9

What is the target of the internal globus pallidus? Which tracts are its axons sent through?

Answer 9

Ventrolateral, Ventroanterior nuclei of thalamus via the lenticular fasciculus and ansa lenticularis

Question 10

What is the target of the substantia nigra pars reticulata?

Answer 10

Ventroanterior nucleus of thalamus, mediodorsal nucleus of thalamus, pedunculopontine nucleus, superior colliculus

Question 11

Name the four basal ganglia-thalamocortical loops:

Answer 11

sensorimotor, oculomotor, orbitalfrontal, prefrontal