Histology of the Cerebellum
By
Dr. A.U. Agu
MBBS, MSc, PhD
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The Cerebellum
• Lies in the posterior cranial fossa.
• Coordinates muscular activity & maintain posture &
equilibrium
• Consists of superficial layer of grey matter – cortex,
& central core of white matter.
• Because of the presence of numerous fissures, the
cerebellar cortex is extensive.
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Subdivisions of the Cerebellum
• The cerebellum consists of a midline part called the vermis, & 2 lateral
hemispheres.
• Has superior & inferior surfaces.
• On the superior aspect, there is no line of distinction b/w vermis &
hemispheres, but on the inferior aspect, the 2 hemispheres are separated
by a deep depression - vallecula.
• The cerebella surface has a series of fissures, which subdivide the
surface into narrow leaf-like bands - folia.
• The long axis of the majority of folia is more or less transverse, & sections
cut at right angles to this axis have a characteristic tree-like appearance
(arbor-vitae ie tree of life).
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Grey & white matters of the cerebellum
• The grey matter is the cerebellar cortex & is superficial to the
central core of white matter.
• Embedded within the central core of white matter are masses of
grey matter that constitute the cerebellar nuclei. Viz
– The dentate nucleus - lies in the centre of each cerebellar hemisphere.
– The emboliform nucleus - lies on the medial side of the dentate nucleus.
– The globose nucleus - lies medial to the emboliform nucleus.
– The fastigial nucleus lies close to the middle line in the anterior part of the
superior vermis.
Scheme to show the placing of the
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cerebellar 4
cortex and nuclei.
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Structure of the Cerebellar Cortex
• The structure is uniform in all
parts of the cerebellum.
• Divided into 3 layers:
– Molecular layer (most superficial).
– Purkinje cell layer.
– Granular layer.
• In addition to purkinje cells, other
cells in the cerebellar cortex are;
– stellate cells
– Basket cells
– Golgi cells
– Brush cells
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The cells/neurons of the
cerebellar cortex are
associated with the layer
in the following ways;
• Purkinje cells - forms
the Purkinje layer
• Granule cells - forms
the granular layer.
• stellate & Basket cells
- lying in the molecular
layer.
• Golgi & Brush cells -
present in the granular
layer. Scheme to show the arrangement of neurons in the
11/27/2024 cerebellar cortex. P=Purkinje cells. 7
Purkinje cells
• The Purkinje cell layer contains
only one layer of neurons.
• The cell bodies of these
neurons are large and flask-
shaped.
• The cells are evenly spaced.
• A dendrite arises from the
‘neck’ of the ‘flask’ and passes
‘upwards’ into the molecular
layer.
• The axon of each Purkinje cell
passes ‘downwards’ through
the granular layer to enter the
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white matter.
Granule cells
• Are very small, numerous, spherical neurons
that occupy the greater part of the granular
layer.
• The spaces not occupied by them are called
cerebellar islands. These islands are occupied
by special synaptic structures called glomeruli.
• Each granule cell gives off 3-5 short dendrites,
which end in endings that enter the glomeruli
where they synapse with the terminals of
incoming (mossy) fibres.
• The axon of each granule cell enters the
molecular layer, & divides into 2 forming a T-
junction.
• These axonal branches of granule cells are
called parallel fibres.
• The parallel fibres run at right angles to the
planes
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Golgi neurons
• Are large, stellate-like cells
lying in the granular layer,
just deep to the Purkinje
cells.
• Their dendrites enter the
molecular layer, branch
profusely, & synapse with the
parallel fibres.
• Some dendrites ramify in the
granular layer.
• They take part in the
formation of glomeruli.
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Clinical correlates
• Cerebellar ataxia – due to damage to the purkinje
cells
– Manifests as poor coordination of voluntary movements
– Causes – familial neurodegenerative disease, alcohol
abuse, tumours, trauma or hypoxia
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Thanks for listening
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