Basal Ganglia Flashcards
head of caudate function
regulates self control, ,and determines relevant information
- goal-directed behavior
- social behavior
body of caudate function
decides about motions of eyes and spatial attention
saccades: rapid eye movements
- oculomotor loop
reflexive prosaccades
rapid eye movements TOWARDS object
antisaccades
rapid eye movements AWAY from object
globus pallidus internus function
main output of basal ganglia
Part of the Go pathway / direct pathway (promotes movement) and final output of basal ganglia
globus pallidus externen function
Modulates the No-Go /indirect pathway (inhibits movement)
putamen function
motor planning
pedunculopontine nucleus function
inhibits reticulospinal tracts –> postural and proximal limb muscle activity (resting muscle tone)
midbrain locomotion region function
excites (ACH) reticulospinal tracts –> walking
Parkinson’s disease
decreased dopamine –> excessive GPi activity –> too much inhibition of motor thalamus, pedunculopontine nucleus, and midbrain locomotor region –> bradykinesia, rigidity of trunk, freezing gait
Huntington’s disease
degeneration of putamen –> loss of GABA neurons –> decreased GPi activity –> less inhibition of motor thalamus, pedunculopontine nucleus, and midbrain locomotor region –> excessive movements and reduced postural control
Dystonia
upregulation of D1 receptors/downregulation of D2 –> overactive Go pathway/underactive No-go pathway –> involuntary sustained muscle contractions
Motor Loop
Oculomotor loop
Goal directed behavior loop
Social behavior loop
Emotional loop
Stop (hyperdirect) pathway
Go ( direct) pathway
No go (indirect pathway)
