basal ganglia Flashcards
what does damage to motor cortex cause?
paralysis/ spasticity
what does damage to cerebellum cause ?
inaccurate/poorly timed movement
e.g. ataxia
what does damage to basal ganglia cause ?
problems initiating and terminating movement
what does the basal ganglia control ?
strategic aspects of movement
no direct connections to spinal cord
what is relevance about basal ganglia connections?
reciprocal connections to cerebral cortex
involved in movement, behaviour and emotion
what are the 5 nuclei in the basal ganglia ?
caudate
putamen
- both part of striatum
globus pallidus
subthalamic nucleus
substantia nigra
role of the striatum ?
receive direct and indirect connections from cerebral cortex
what 2 nuclei does the striatum project to ?
globus pallidus
substantia nigra -forms indirect pathway
in the feedback loop what type of input does the basal ganglia receive from the cerebral cortex ?
excitatory
when an excitatory input is received from the cerebral cortex in the feedback loop what signals are sent to the thalamus ?
inhibitory
what surpasses motor cortical activity in the feedback loop ?
inhibitory signals from the cerebral cortex to the thalamus
what does excessive basal ganglia input cause ?
slow movement
what does reduced input for the basal ganglia cause?
enhanced movement
what does the cerebral cortex, basal ganglia and thalamus form ?
transcortical loop
comprises of 3 stages
what are the 3 stages in a transcortical loop ?
striatum receives inputs from cerebral cortex
output from globes pallidus internal and substantial nigra (pars reticular) project thalamus - inhibitory signal
inhibited thalamus projects to motor cortex, supressing movement
