Upload
others
View
8
Download
0
Embed Size (px)
Citation preview
Cerebellum
Lec 12
Purves, 18-5
Functional regions of cerebellum
Cerebrocerebellum (hemispheres): coordination of voluntary movements, cognitive role?
Spinocerebellum &Vestibulocerebellum (midline):posture and balance, eye movements
What kinds of information doesthe cerebellum receive?
somatosensoryvestibular
auditory
visual
proprioceptive
Cerebellar circuit diagram
inputs arrive at the cerebellar cortex
The cerebellum is a fast feedback loop that helps smooth and coordinate all movements
the cortex processes the informationand projects to the deep nuclei
the deep nuclei generate the output.
CEREBELLAR CORTEX
Deep nuclei
Rednucleus
Inferiorolive
Vestibularnuclei
ThalamusVL
CerebralCortex
from Purves, 18-6
Principal OUTPUTS from the cerebellum
Superiorcerebellarpeduncle
Primary motor Cx
Premotor Cx
Thalamus(VL) Superior cereb.
peduncle
Pons
Deepcereb.nuclei
Vestib. nuclei
Inf. olive
The cerebellar microcircuit
Deepcerebellar
nuclei
Inferiorolive All other
inputs
clim
bin
g fi
be
r
mo
ssy
fib
er
parallel fiber
Purkinjeneuron
granule cell
+
+
+
cortex
Golgicell
Basketcell
Stellate cell
+
++
VestibularPonsSpinal cord
+
+
+
CortexRed nucleusSpinal cord
Symptoms:Nausea - vomitingDizzinessVertigoHand shakingImbalanceFallsClumsinessSlurred speechDouble visionDifficulty concentrating
Cerebellar dysfunctionNeurological signs:Ataxia TremorDysdiadochokinesisDysarthria and scanning speechNystagmusHypotoniaCerebellar ataxia (Romberg test)DysmetriaDiplopiaCognitive dysfunction
Summary
1. The cerebellum “balances” motor commands and sensory information to smooth and coordinate movement.
2. Lesions of the cerebellum cause ataxia, tremor, balance and posture problems.
3. Inputs to cerebellum: mossy fibers (pons & spinal cord) & climbing fibers (inferior olive).
4. Purkinje neurons use the neurotransmitter GABA and inhibit their targets in the deep nuclei.
5. Outputs from cerebellum: deep nuclei to red nucleus, thalamus, inferior olive, and vestibular nuclei.
6. Associative forms of motor learning occur in the cerebellum.
7. Think of the cerebellum when you’re in the ER
This is cerebellum!