cerebellum and basal nuclei Flashcards
where are the basal nuclei situated?
base of the forebrain
what are the basal nuclei strognly intercocnnected with?
- cerebral cortex
- thalamus
- brainstem
what are the components of the basal nuclei?
caudate nucleus
putamen
globus pallidus (internal and external)
substantia nigra (pars compacta and pars reticulata)
nucleus accumbens
claustrum
amygdala (limbic system)
role of the caudate nucleus and the putamen
input region of the basal nuclei and
they are separated by the internal capsule
what do the putamen and caudate nucleus form?
striatum
what do the globus pallidus and putamen form?
lentiform/lenticular nucleus
what areas of the basal nuclei are output regions that project to the thalamus?
internal segment of the GP (GPi) and the pars reticulata of the substantia nigra (SNr)
what area of the basal nuclei have dopamine-containing neurons that project to the striatum?
pars compacta of the substantia nigra (SNc)
role o fthe nucleus accumbens
forms part of the ventral striatum involved in motivation and reward
difference between SNc and SNr
pars compacta made up of dopaminergic neurons
pars reticulata made up of GABAergic neurons
uniform cytoarchitecture of the cerebellum
regional differences in function due to differences in input and output connections
cerebellum has 3 layers: molecular, purkinje and granular
what area of the brain is the cerebellum closely associated with?
dorsal surface of the midbrain
what are the 4 spinal cord inputs?
dorsal spino-cerebellar tract
ventral spino-cerebellar tract
cuneo-cerebellar tract
rostral spino-cerebellar tract
what is the dorsal spino-cerebellar tract (DSCT)?
input from the lower limbs via the inferior peduncle
what is the ventral spino-cerebellar tract (VSCT)?
input from the lower limbs via the superior peduncle
what is the cuneo-cerebellar tract (CCT)?
input from upper limbs via the inferior peduncle
what is the rostral spino-cerebellar tracts (RSCT)?
input from the lower limbs via the inferior peduncle
DSCT and CCT information
detailed external proprioceptive information using muscle spindles
VSCT and RSCT information
intergrated, internal proprioceptive information using golgi tendon organ
which is the pathway that comes through the superior peduncle?
VSCT
role of the spinal cord inputs
convery unconscious proprioception and pass mainly ipsilaterally to the anterior lobe and vermis
inputs into the cerebellum via the cerebral cortex happens via the…
cortico-ponto-cerebellar pathway
role of cortico-ponto-cerebellar pathway
from the cortex, decussates and then sends contralteral information
from the middle peduncle it will send informatiom to all areas of the cerebellar cortex (especially the lateral hemisphere)
role of the vestibular nuclei
fibres pass ipsilaterally to the inferior peducnle to the flocculo-nodular lobe
role of the reticular formation
fibres mainly ipsilaterally to the inferior peduncle to all parts of the cerebellar cortex
role of the inferior olivary nucleus (ION)
contralateral inferior peduncle and ends as climbing fibres in all parts of the cortex
all sources of cerebellar input and all targets of its output give input to the ION
what are the two types of inputs into the cerebellum?
climbing fibres and mossy fibres
what are climbing fibres?
come from the ION and end on purkinje cells
low level of basal activity
what are mossy fibres?
from all other afferents and end om granule cells
spontaneous activity and movement related
what are cerebellar cortical zones?
individual zones defined by idfferences in purkinje cell output and climbing fibres input from different parts of the inferior olive
spinocerebellum role
vermis and intermediate hemisphere
control of limbs and trunk
cerebrocerebellum role
lateral hemisphere
planning of movement
vestibulo-cerebellum role
floculu-nodular lobe
control of eye and head movements and balance
what are the 3 cerebellar cortical divisions?
spinocerebellum
cerebrocerebellum
vestibulo-cerebellum
cerebellar outputs to the spinal cord
there are no dircet outputs to the spinal cord
info flows from cerebellar cortex to deep cerebellar nuclei and the out which influences motor planning and execution
what is the lateral hemispheric cortex path?
from the dentate nucleus which outputs via superior peduncle to the cerevral cortex via the ventral lateral nucleus in the thalamus
involved in pre-preogramming movements
what is the paravermal cortex path?
goes to globose and emboliform nuclei and putputs to the superior peduncle to the red nucleus and to the lateral descending pathway
(rubrospinal)
involved in motor execution
what is the vermis path?
to the fastigial nucleus which outputs cia inferior peduncle to medial descedning pathways
involved in motor exectution
what is the flocculo-nodular path?
fastigial nucleus and outputs to inferior peduncle to vestibular nuclei and reticular formation
involved in control of posture and balance and eye movement coordiation