Basal Ganglia Flashcards
What are the functions of the basal ganglia? (5)
- Provides foundation from which cortex can direct purposeful movement
- Serves as feedback mechanism to cerebral cortex for initiation and control of movement
- Provides strong influence over initiation and control of movement
- Influences prefrontal oculomotor control
- Involved in limbic regulation of emotion and motivation
The neostriatum is made of what two structures?
Caudate nucleus and Putamen
What structures are considered basal ganglia?
- caudate nucleus
- Putamen
- Globus Pallidus
- Subthalamic nucleus
- Substantia nigra
Which structures receive input?
Caudate Nucleus
Putamen
This structure receives input from frontal eye fields, cortical association cortex, and limbic structures
Motivation to move
Caudate Nucleus
This structure recieves input from M-1, secondary motor, S-1 Cortial input viva CM nucleus of thalamus. This is more motor and less cognitive emotional
Putamen
Name the steps of the direct pathway
Cortex-> neostriatum_> globus pallidus-> motor pathway
Name the steps of the indirect pathway
Cortex–neostriatum–globus pallidus–subthalamic nucleus
Name the three output structures
Globus Pallidus
Substantia Nigra
Subthalamic nucleus
This output structure is associated with reciprocal connections with globus pallidus
Subthalamic nucleus
This output structure is associated with dopamine production. Receives input rom neostriatum, gives output to neostriatum and is a filtering/processing center
Substantia nigra
This output structure is associated with projecting back to the motor cortex via the thalmus
globus pallidus
T/F Activation of cortex direct pathway increases motor
True
T/F Activation of indirect pathway inhibits motor planning
True
What are three important neurotransmitters in the basal ganglia?
Dopamine + -
GABA -
GLU+
T/F Increased dopamine means decreased allowance of movement
False
NAme this disorder:
Absense of movement
akinesia
Name this disorder:
Slow movement
bradykinesia
Name this disorder:
Release of unintentional movements during rest
dyskinesia
Increased muscle tone
Rigidity
T/F In PD, motor accuracy is also affected.
False
The hallmark of PD is?
Loss of dopamine producing cells in the substantia nigra
Where is dopamine produced? 3 places
substantia nigra
ventral tegmentum (nucleus accumbens)
Hypothalamus
Name disease characteristics of PD
Bradykinesia and akinsesia rigidity tremor impaired postural mechanisms slowed gait, short steps loss of facial expression monotone speech
What are the nonmotor symptoms of PD
depression autonomic dysfunction sleep disorder cognitive impairment gait/balance problems
The first signs of this genetic disease are clumsiness and slurred speech
Huntington’s Disease
What is the cause of HD?
loss of GABA- cells in striatum(decreases activity of indrect pathway, therefore increasing movements)
Names this disease?
Follows lesions to the subthalamus. Characterized by flinging, rotary movements
Hemiballismus
primary symptom is involuntary facial movement. Associated with prolonged use of antipsychotics
Tardive dyskinesia
T/F Tic disorders are associated with DA+- dysfunction
True
T/F The CB gets input from the cord, and the BG does not
True
