Basal Gangila Flashcards
Basal Ganglia
-motor control and adjustments (no direct contact to motor neurons)
-initiate and inhibit movements
-goal-directed
-social behavior
-emotions
Parts of Basal Ganglia
Caudate
Putamen
Caudate+Putamen= Striatum
Anterior/Nucleus Stiatum
Putamen + Globis Pallidus= Lentiform Nucleus
Globis Pallidus Internus
Globis Pallidus Externus
Subthalamic Nucleus
Substantia Nigra
Substantia Nigra
-produces dopamine
-in midbrain
-mood, learning, judgement, descion making
Has
-Substantia nigra compata
Substantia nigra reticularis
Subthalamus/Subthalamic Nuclei
-superior to substantia nigra
-inferior to thalamus
-Lateral to hypothalamus
-functionally a part of basal ganglia
-initiates and suppresses movement
-excitatory input to basal ganglia
Inputs to Basal Ganglia
-From Cerebrum Through Corticostriatal pathways
-From Striatum
-Glutamate; excitatory
-Dopamine; excitatory
-ACH; excitory
-Serotonin; inhibitory
Outputs from Basal Ganglia
-Out of Globus Palliidus Internus
-Out of Substantia Nigra
-GABA; Inhibitory
Motor Loops
-oculomotor loop
-Motor loop
Non-Motor Loops
-Goal-directed behavior loop
-social behavior loop
-emotion loop
Goal-Direct Behavior Loop
- Lateral prefrontal Cortex
- Head of Caudate: descision making, planning and picking actions
- GPi
- Thalamus: linking action chosen by caudate and performing movement
- Lateral Prefrontal Cortex
Deficits: inattention, poor concentration, disorientation, poor short term memory
-dorsal striatal and prefrontal
Social Behavior Loop
- Ventral Prefrontal Cortex
- Head of caudate: social cues, self control, determines irrelevant
- Substantia Nigra Reticularis
- Thalamus
- Ventral Prefrontal Cortex
-dorsal striatal and prefrontal
Deficits: inppulsivity, indifference, temper, risky behaviors
Emotion Loop
- Medial Prefrontal Cortex
- Ventral Striatum: emotions and motivation; links emotional, cognitive and motor systems
- GPs
- Thalamus
- Medial Prefrontal Cortex
Deficits: L BG stroke causing depression and dull emotions, impaired reward seeking
-ventral striatal and limbic channel
Oculomotor Loop
- Frontal and Supplementary Eyes Fields
- Body of Caudate: eye motions and spacial attention (rapid eye mmts)
- Substatia Nigra
- Thalamus
- Frontal and Supplementary Eyes Fields
-dorsal striatal and oculomotor loop
Deficits: poor saccadic eye mmts
Motor Loops
- Motor and Premotor Cortex
- Putamen: motor planning
- Globus Pallidius
- Thalamus
- Motor and Premotor Cortex
-dorsal striatal and motor channel
Deficits: muscle contractions and force, sequencing
-no caudate
Disinhibition
-2 inhibitory neurons target 1
-2nd inhibitory neuron inhibits the first to allow excitatory activity
-fine tuning movements
Motor Loop Internal Pathways
Stop
Go
No-Go
-all of GPi as output nucleus; inhibits motor thalmus to excite cortical motor areas to excite motor neurons
-cause excessive or insufficient movement