Test 2 Review Flashcards
What are the two parts of the corpus striatum?
caudate nucleus and putamen
What are the two parts of substantia nigra?
pars reticulata and pars compacta
What is the major role of the basal ganglia?
permission for initiation of movement by the upper motor neurons
Where do the medium spiny neurons receive input from?
from the cortex
What kind of input do MSNs receive?
Excitatory from glutaminergic synapses
Firing of MSNs is associated with _____ _______.
impending movement
The caudate is associated with ____ movements.
eye
The putamen is associated with ___ and ____ movements.
limb; trunk
When is tonic inhibition inhibited?
when the straitum is activated
When the thalamus is disinhibited what happens?
it can signal the upper motor neuron
What does the direct pathway do?
it facilitates initiation of volitional movement
What portion of the GP do the MSNs project to in order to tonically activate inhibitory neurons?
GPi (internal portion)
Disinhibition allows ______ of the upper motor neurons.
activation
Disinhibition of inhibitory synapse on thalamus = ________
movement
MSNs in straitum project to ____ ____ which then sends ________ projections back to the MSNs.
pars compacta; dopaminergic
D1 receptors are _____ GPCRs and they act on the ______ pathway.
excitatory; direct
D2 receptors are _____ GPCRS and they act on the _____ pathway.
inhibitory; indirect
D1 and D2 receptors both _____ inhibitory outflow to ______ excitability of UPM.
decrease; increase
Loss of _______ ______ neurons contributes to Parkinson’s disease.
nigrostriatal dopaminergic
Which pathway has sustained inhibition?
direct pathway
How does the indirect pathway impact the direct?
It augments direct pathway inhibition
What is a characteristic of inhibitory outflow in Parkinson’s disease?
it is abnormally high from the basal ganglia
What happens to inhibitory outflow of the basal ganglia?
upper motor neurons are activated by inappropriate signals
What causes Huntington’s?
a defective gene
How do you treat Huntington’s?
alleviate symptoms by blocking DA transmission (anti-psychotics)
What is the main function of the cerebellum?
error correction: it reduces the error and provides precision
____ _____ ____ are the main output with input from the cerebellar cortex.
deep cerebellar nuclei
What are the three divisions of the cerebellum?
1- cerebrocerebellum
2- spinocerebellum
3- vestibulocerebellum
What is the major function of the cerebrocerebellum?
execution of complex spatial and temporal sequences of movement
Where does the cerebrocerebellum receive input from?
directly from the cortex
Where is the cerebrocerebellum?
the lateral sides of the cerebellum
Where is the spinocerebellum?
median and paramedian zones
Where does the spinocerebellum receive input from?
directly from the spinal cord
What is the function of the spinocerebellum?
medial to lateral (in relation proximal to distal) regulation of muscles
Where is the vestibulocerebellum?
caudal-inferior lobes
Where does the vestibulocerebellum receive input from?
vestibular nuclei
What is the function of the vestibulocerebellum?
regulation of posture and equilibrium
What are the three cerebellar pathways?
1- middle cerebellar peduncle
2- inferior cerebellar peduncle
3- superior cerebellar peduncle
Which cerebellar peduncle(s) is/are afferent pathways?
middle cerebellar peduncle and inferior cerebellar peduncle
Where does the middle cerebellar peduncle receive input from?
the pontine nuclei
Where does the inferior cerebellar peduncle receive input from?
vestibular nuclei, spinal cord, and brainstem
Which cerebellar peduncle(s) is/are efferent pathways?
superior cerebellar peduncle
Where does the superior cerebellar peduncle give input to?
deep cerebellar nuclei to thalamus, motor cortex, and superior colliculus
______ ______ and superior colliculus neurons synapse on ______ ______.
cerebral cortex, pontine nuclei
Pontine nuclei relay inputs via ____ ______ ______>
middle cerebellar peduncles
Where does the inferior olive receive inputs from?
cortex, reticular formation, and spinal cord
Where does the inferior olive project to?
cerebellum via inferior cerebellar peduncle
What does the inferior olive do?
participates in learning and memory
What are the three layers for the cerebral cortex?
molecular, Purkinjie, and granule
What do input from pontine nuclei to cerebellum cross?
via mossy fibers
Input from pontine nuclei synpase on ____ ____ which give rise to parallel fibers that ascend to _____ ______.
granule cells; molecular layer
Input from pontine nuclei system also synapse on dendrites of _____ _____ (output cells).
Purkinje cells
Purkinje Neuron Input = _____ _______ ______
error correction signal
Purkinje neurons in cerebellar cortex shapes _____ _____ generated by deep buclei neurons being excited by mossy and climbing fiber input.
discharge patterns
How fast is cerebellum modification of movement?
it’s done in real time
Modulation of ongoing movement leads to complex neuronal responses of both ____ __ and deep cellular nuclei whose timing is associated with the ___ _____.
Purkinje cells; motor function
What is cerebellar ataxia?
difficulty in producing smooth coordinated movements
What does movement look like in cerebellar ataxia?
jerky, imprecise actions and staggering gait
How does alcohol abuse impact movement/cerebellum?
affects lower limb and anterior spinocerebellar region
What does a lesion of vestibulocerebellar region lead to?
imbalance and nystagmus
What does a cerebrocerebellar lesion lead to?
impaired learning of movements (i.e. guitar playing)
___ ____ _____ from 3 motor nuclei innervate the extraocular muscles.
lower motor neurons
Where does the abducens (CN VI) exit the brainstem?
from pons medullary junction
What does the abducens innervate?
lateral rectus muscle
Where does the trochlear nerve (CN IV) exit the midbrain?
caudal portion
What does trochlear nerve innervate?
superior oblique muscle of eye
Where does the oculomotor nerve (CN III) exit midbrain?
rostral midbrain just medial to the cerebral peduncle
What are the two gaze centers?
horizontal and vertical; aka Paramedian Pontine Reticular formation and Rostral Interstitial nucleus
What do the two gaze centers do?
innervate motor nuclei and eye muscles
Activation of gaze centers in concert results in ____ ____.
oblique movements
Where does input from the retina and visual cortex go to?
the superior colliculus
Superior colliculus (and frontal eye field) neurons are activated by ___ ____ and firing generates ____ ____.
visual stimuli; saccade movements
The frontal eye fields project to what two places?
1- superior colliculus
1- reticular formation gaze centers
The frontal eye fields are essential for scanning visual field to locate _____ of _____ among distracting objects.
object of interest
Lateral inhibition in frontal eye fields has what effect?
it enhances neural responses to the object of interest
What is the function of the sympathetic nervous system?
fright, flight, fighting and fornication
What is the function of the parasympathetic nervous system?
produces energy
What NT(s) do(does) the parasympathetic nervous system use?
only ACH
What NT(s) do(does) the sympathetic nervous system use?
ACH, epinephrine, norepinephrine
Where is the innervation from the spinal cord in the sympathetic nervous system?
thoracic and lumbar
Where is the innervation from the spinal cord in the parasympathetic nervous system?
brainstem and sacral
Sympathetic ganglion cells (mostly) release ______ on _____ cells.
norepinephrine; target
Parasympathetic ganglion cells use only ______.
acetylcholine
What does the central autonomic network of the NTS do?
it coordinates integrative and voluntary controls of viscera and combines with emotion to make other functions happen
What is the function of the nucleus of solitary tract?
it is the relay center for visceral sensory and motor integration
Where does the nucleus of solitary tract provide input to? 3 places
1- visceral motor nuclei
2- reticular formation premotor cortex
3- integrative centers in amygdala and hypothalamus
What is the Babinski reflex a sign of?
an upper motor neuron lesion
How is the ventral horn organized?
topographically: proximal to distal is medial to lateral respectively
What is the difference between an alpha and gamma cell?
Add answer
What is a golgi tendon and what does it do?
it senses muscle tension and sends a signal to alpha and gamma cells to propogate
Why does a single alpha neuron innervate different muslces?
so that it’s loss does not impact movement too much and so that the force is spread evenly throughout the muscle
What is the function of inhibitory neurons in the muscles?
they create opposition to contraction (aka the muscle relaxes)
What happens when a muscle is activated?
it contracts
Where is the internal capsule?
it connects the forebrain to brainstem
What is the function of the internal capsule?
its like a highway
What do the connections of the internal capsule allow?
creation of movement
What is the corticospinal tract responsible for?
conducts impulses from the brain to the spinal cord and is involved in voluntary movement
What is the corticobulbar tract responsible for?
posture, balance, gaze
Why is the pyramidal tract called this?
because they pass through the pyramids of the medulla.
What are the extrapyramidal tracts important to?
vestibular related movement
What is the lateral corticospinal tract responsible for?
highly skilled movement of distal limbs (aka fingers)
Most movement originates ________.
contralateral
What is another name for superior and inferior colliculus?
tectospinal tract
What is the superior colliculus responsible for?
visual information
What is the function of the colliculospinal tract?
it adjusts head movement (nonvestibular info)
How are the 3 extrapyramidal tracts divided?
functionally
Motor cortex is organized by _____ not ______.
movement; topographically
What cells are in cortical layer 5?
Betz cells
30% of upper motor neurons start from ____ _____.
premotor cortex
When did the monkey’s mirror cells light up? 4 times
1- when the monkey made the action
2- when others made the action
3- when it observed its own action
4- when the action was performed behind a screen
When did the motor neurons of the monkey not light up?
When other monkeys used tools
What projects to MSNs?
striatum
Where do MSNs project to?
globus pallidus
What type of signal do the MSNs take/give?
excitatory and inhibitory (respectively)
How is motor created in relation to the basal ganglia?
by disinhibition of
What is Parkinson’s in relation to the function of the basal ganglia?
too much inhibition which limits movement
Does the cerebellum initiate movement?
no it just corrects
What is the main input to the cerebellum?
the pontine nuclei
What is the inferior olive involved in?
muscle memory
Is vestibular info contra or ipsilateral?
ipsilateral
Vestibular info projects through ___ ____.
mossy fibers
What is the main source of cerebellar output?
Purkinje fibers
Climbing fibers –> ______ –> Deep cerebellar nuclei
Purkinje fibers
How is the spinocerebellum organized?
topographically
How many gaze centers are there?
2
Where does the superior colliculus take input from?
the contralateral side
How is information in the superior colliculus organized?
it retains the topography of the outside world
