lecture 9: motor control Flashcards
function of the thalamus:
relay center for nervous system
nuclei of the thalamus:
- anterior nucleus:
- ventral anterior:
- ventral lateral:
- centromedian:
- dorsal medial nucleus:
- limbic lobe (memory formation, emotional processing)
- supplementary motor area and frontal lobe (executive functioning)
- input from substantia nigra (controls body movements)
- gate keeper of thalamus
- role in limbic system and emotional processing
what parts of the basal ganglia make up the striatum? lentiform?
- caudate, nucleus accumbens, putamen
- putamen & globus pallidus (external & internal segments)
pars compacta is located in _______ region of substantia nigra.
pars reticulata is located in ________ region of substantia nigra
posterior
anterior
what are general functions of the basal nuclei?
psychomotor functions (planning, coordination, execution)
cognition
emotion
what are the nuclei that project in aka afferent pathway to basal nuclei system?
cerebral cortex
thalamus
substantia nigra, pars compacta (however, NOT strictly afferent)
what are the nuclei that project out aka efferent pathway to basal nuclei system?
globus pallidus, internal segment to the thalamus for body motor functions
substantia nigra, pars reticulata to superior colliculus for eye movement
_______ _________ is the basic pattern for neural circuit function
spatiotemporal innervation
what is the gate keeper of the basal nuclei system? where is it mainly located?
medium spiny neuron
in striatum of basal nuclei
Substantia Nigra Pars Compacta:
Functions: Involved in ________ both direct and indirect pathways.
modulating
Efferent Pathways:
Globus Pallidus Internus (GPI): Receives signals from both pathways, playing a role in ________ thalamic activity.
Pars Reticulata (SNpr):
Functions: Sends inhibitory signals to _________, affecting overall motor output.
inhibiting
thalamus
Direct Pathway
Goal: Activating _______ programs.
Convergence Projection: _______ medium spiny neurons —> single neuron in GPI
Analogy: Team effort—multiple players (MSNs) working together to initiate a specific movement.
“wanted”; multiple
Indirect Pathway
Goal: Inhibiting _________ programs.
Divergence Projection: _________ medium spiny neuron -> Multiple neurons in GPI
Analogy: One player (MSN) saying, “Hold on, let’s not do that,” influencing others to stop certain movements.
“unwanted”; single
cerebral cortex directly activate subthalamic nucleus is known as _________ pathway
hyper-direct
parafasicular nucleus directly activate subthalamic uncles is known as _______ pathway
super-direct pathway
Both the hyper-direct and super-direct pathways are major _____ excitatory input.
subthalamic
________ Inhibition by GPI
Continuous, steady inhibition. Acts as a “brake” on thalamic activity for fine-tuning motor control.
Tonic
Inhibition from Left Prefrontal Cortex
Essential for _______ Execution. Crucial for preventing _______ movements.
Functional; unwanted
Parkinson’s Disease Pathophysiology is caused by 3 things:
total effect: Difficulty to Initiate _________ activities with extra ________ activities.
- Death of Dopaminergic Neurons in SNpc
- Decreased Excitatory Effects on Direct Pathway
- Decreased Inhibitory Effects on Indirect Pathway
“Wanted”; Unwanted
How does the decreased activation of the direct pathway impact intentional movements in hypokinetic disorders (parkinson’s)?
Akinesia is ______, rigidity is _______ and _______ to limb movement, and bradykinesia is ________ _of movement.
inhibits “wanted” programs (decreased/inhibited) , leading to difficulty initiating and executing purposeful movements.
no movement at all, stiffness/resistance and slowness.
How does the decreased activation of the indirect pathway impact intentional movements in hyperkinetic disorders (huntingtons)?
Dyskinesia: unique _____ tremor (pill rolling)
inhibits “unwanted” program (increased/activated)
resting *movement not coordinated
clinical management of Parkinson’s disease?
answer:
1. ________ therapy
2. ______ treatment
-drug?
3. _______ management: ______/_____ removal: unexpectedly ______. Deep brain _______
What is the most affective:
physical
medical; L-dopa (increases dopamine levels)
surgical; VA/VL; effective
stimulation
combination
Which neurons are the ONES in charge of efferent functions in cerebral cortex cerebellar cortex, and striatum of basal nuclei?
GPI, SNpr
Huntington’s disease = enlarged _______ ventricle and entirely lost ________ .
Starts to show around at what age? Indirect pathway lost at?
lateral; caudate
30-50 yrs. old
GPe
Damage to subthalamic nucleus is known as ______. Unilateral or bilateral affects of the body?
hemiballismus
