Basal ganglia Flashcards
what is the primary influence of the extrapyramidal system upon?
the primary and premotor cortices
what forms the anterior portion of the substantia nigra?
the pars reticularis
what does the pars reticularis contain?
serotonin and GABA
What does the pars compacta contain?
dopamine and melanin
Which neurons in the substantia nigra are principally destroyed in parkinson’s disease?
the neurons in the pars compacta
what is a sign/symptom of a unilateral lesion of the subthalamus?
contralateral hemiballisums
what comprise the ventral striatum?
the nucleus accumbens and olfactory tubercle
what is the nucleus accumbens involved in?
encoding new motor programs and cognitive processing of aversion, motivation, reward, and reinforcement learning
what kind of behavior is the nucleus accumbens associated with?
addictive behavior
what are often called the motor nuclei of the thalamus?
the ventral anterior and the ventral lateral nuclei
what type of fibers are the nigrothalamic fibers?
non-dopaminergic
where do the nigrothalamic fibers originate?
pars reticularis
what type of fibers are nigrostriatal fibers?
dopaminergic fibers
where do the nigrostriatal fibers originate?
in the pars compacta of the substantia nigra
what destruction is involved in Huntington’s chorea?
destruction of the inhibitory, gaba-nergic fibers in the striatonigral fiebrs
what kind of fibers are the striatonigral fibers?
gaba-nergic fibers
are the pallidothalamuc and nigrothalamic fibers excitatory or inhibitory?
inhibitory
acute anterior poliomyelitis selectively involved what?
the motor neurons of the anterior horns and the cranial nerve motor nuclei
What leads you to suspect ALS? (amyotrophic lateral sclerosis)
LMN and UMN degeneration
what are the common features of huntington’s chorea?
dementia, chorea, and behavioral disturbances
What are the principal areas of degeneration with cases of huntington’s chorea?
corpus striatum and the cerebral cortex
degeneration of the corpus striatum and cerebral cortex result in what?
excessive dopaminergic influence in the degenerated striatum or loss of inhibition from the GABAnergic nerons of the striatonigral pathway
what do unilateral lesions of the subthalamus result in? (not the disorder)
a reduction or loss of glutamate inhibition upon the globus pallidus
