Basal Ganglia Flashcards
Indirect pathways (movement) ?
Inhibits movement
Direct pathways (movement)?
Facilitates movement
Normal action and output of the BG is dependent on?
The balance of direct and indirect pathways
Substantia nigra pars compacta releases ?
Dopamine (neurotransmitter)
Output of BG is..?
Inhibitory
Direct pathway facilitates movement how?
Reducing inhibitory output to thalamus (excitation of cortex)
Indirect pathway reduces movement by?
Increasing he inhibitory output to thalamus (inhibition of cortex)
Pathway from substantia nigra (PC) excites and inhibits which pathways ?
Excites direct
Inhibits indirect
Sub nigra pathway (PC) facilitates or reduces movement?
Facilitates
BG function
Motor, cognitive (memory, attention,modivation)
BG motor function
Regulating automatic movements unconsciously
Repetitive movements
Motor function: 2 main proposed functions:
Internal cue or trigger
Cortical motor set
Internal cue?
Plastic inhibition of cortical regions
Provides cue to switch between submovements of a sequence
Cortical ‘motor set’ ?
Preparation maintenance of motor plans in a state of readiness for action e.g sets parameters for action
Enables motor functions to be carried out functionally and appropriately
Inhibition of undesired movements
Maintenance of muscle tone and posture
Adapting movements to enviro
Modulating reflexes to the current task demands e.g postural reflexes or walking,turn off gastrocs in swing
Internal cue pathway
BG
Cortical regions
CST
Voluntary movement
