Flashcards in lecture 7 basal ganglia Deck (39)
what are the five major nuclei of the basal ganglia?
-globus pallidus- internus and externus
what two nuclei make up the striatum?
caudate nucleus and putamen
what two nuclei make up the lenticular nucleus?
putamen and globus pallidus
where does the caudate nucleus run?
runs with the lateral ventricle
where is the lenticular nucleus?
deep to the insula
-putamen- most lateral, joined to caudate head at the ventral striatum (includes nucleus accumbens)
-globus pallidus- pointed medially
where is the substantial nigra located?
2 parts in the rostral midbrain, between the cerebral peduncles and the red nuclei
where is the sub thalamic nuclei located?
inferior to the thalamus
what the functions of the basal ganglia nuclei?
-muscle contraction regulation: force, multi joint coordination, sequencing, imitation of learned sequences of movement
-input from cortex
true or false the direct circuit is inhibitory to the cortex
false the direct circuit excites the cortex
true or false the indirect circuit inhibits the cortex
what are the 3 primary inputs in the circuitry?
-premotor and sensorimotor cortex to putamen to globus pallidus internus to ventrolateral thalamus
-cortex to caudate to globus pallidus internus to ventrolateral thalamus
-subthalamic nuclei to globus pallidus to ventrolateral thalamus
what are the 2 primary outputs to the circuitry?
-globus pallidus- GABA inhibitory n. via ansa lenticularis and lenticular fascicles bundles to thalamus
-substantia nigra reticularis- GABA inhibitory to thalamus
what 5 types of neurotransmitters can be found in the basal ganglia?
what are the two types if dopamine receptors and where do the originate?
originate in the substantia nigra
-D-1: excites the direct path
-D-2: inhibits the indirect path
True or false: both D-1 and D-2 impact the different paths by increases excitation to the cortex
where is the nucleus accumbens?
where the head of the caudate and anterior putamen meet
what is the nucleus accumebens?
collection of GABA inhibitory cell that connect with
-globus pallidus>dorslamqdial thalamus> prefrontal cortex
-substanita nigra and pontine reticular formation
where does the nucleus accumbens get input from?
amygdala and ventral tegmentum
what are the roles of the nucleus accumbens?
-drug addiction via increased dopamine in cells
-musical effects on emotion
What are positive signs and list 7 examples
positive signs are involuntary muscle contractions; something you can see
what are negative signs and list 2 examples
negative signs are lack of muscles contractions; things you can't see
what is a resting tremor?
positive sign: rhythmic oscillations
what is rigidity?
positive sign: increased resistance to movement in all muscles, hypertonicity
what is chorea?
positive sign: continuous rapid movements (degradation of the caudate nucleus seen in Huntington's)
what is dyskinesia?
positive sign: involuntary movement during a voluntary action
what is dystonia?
positive sign: involuntary sustained muscle contraction
what is athetosis?
positive sign: writhing movements (stratal lesions)
what is ballism?
positive sign: fast movement of whole limbs (lesions of contralateral sub thalamic nuclei)
what is bradykinesia?
negative sign: slow movements
what is hypokinesia or akinesia?
negative sign: few or no movement (reduced dopamine from substantia nigra to stratum- parkinson's)
-lead pipe rigidity
-cog- wheel rigidity
what two structure degenerate in Parkinson's?
substantial nigra and pedunculo pontine nuclei
what are the 2 signs or Parkinson's?
-hypokinetic- movement freezing, postural instability, reduced imitation of movement
-hyperkinetic- rigidity, resting tremors
what are the 3 treatments for Parkinson's?
-Deep brain stimulation, ablation, or neuronal transplants/ stem cells
-Optokinetic triggering for smoother movement patterns
what are the 2 causes of Huntington's?
-degernation of striatum and cortex
what are the signs of Huntington's?
-hyperkinetic- continuous movement in dancelike or writhing patterns
what are the 2 treatments for Huntington's?
-management of psychological changes
-medications to slow progression rate, control motor symptoms, block excitotoxins that disrupt energy metabolism of cells
what are the 2 pathologies for dystonias?
-genetic: focal, involuntary sustained contractions
what are the symptoms of dystonias?
-movement decomposition, decreased isolation of digits