Histology of cerebrum and cerebellum

1. HISTOLOGICAL FEATURES OF
CEREBRUM
CEREBELLUM
Prof.J.Anbalagan

2. CEREBELLUM

3. CEREBELLUM
• Hind brain-
– small brain
• Posterior cranial fosse
• Forms roof of IV ventricle
• Fissures and folia

4. CEREBELLUM
• Receives sensory data
– Same side spinal cord
– Dorsal and ventral
spinocerebellar tract
• Receives Motor data
– from cerebrum opposite
side
– Cortico pontine fibers
• Output is motor in function

5. CEREBELLUM
• Cerebellum
–controls the activity of cerebrum and
spinal cord
–dysfunctions
• manifested by disturbances in the motor
functions without voluntary paralysis
• Resulted in clumsy, poorly coordinated
loss of skillful movements

6. CEREBELLUM-Functions
• Responsible for
Equilibrium
Controls eye and head movements
balancing
Postural changes
Muscle tone
Smooth execution of voluntary
movements
Accuracy
Perfection
control

7. White fibers - afferent
• Mossy fibers
– Spinal cord
– Vestibular nucleus
– Pons
• Enters through inferior and middle cerebellar
peduncle
• Synopses with Purkinje cells through granular
cells

8. White fibers- afferent
• Climbing fibers
– Olivary nucleus
– Accessory olivary nucleus
• Through inferior peduncle
• Enters directly to molecular layer
• Synapses with Purkinje 1:1

9. White fibers - efferent
• Axons of Purkinje
( except archicerebellum)
• Deep nuclei of
cerebellum
• Through superior
cerebellar peduncle

10. Cerebellum-cortex
• Pia mater
• Cortex and white fibers
• Cortex-Three layers
• Type of cells
– Stellate cells
– Basket cells
– Purkinje cells
– Granule cells
– Golgi type II
• White fibers
– Climbing fibers
– Mossy fibers

11. CEREBELLUM• Layers of cerebellum
• Molecular layer
– Dendrite orborization
– Densely packed axons run
parallel to surface
– Superficially stellate cells
– Deeper stellate cells
known as basket cells
• Purkinje layer
• Granular layer
– Closely packed granule
cells
– Shows clear zones -
glomeruli

12. CEREBELLUM

13. PURKINJE NEURON
Stellate cells
Basket cell

14. CEREBELLUM-GOLGI STAIN
PURKINJEE NEURONS

15. Cerebellum-dendrite tree

16. Cerebellum-granular layer-(rosette)

17. Molecular layer
Granular layer
Purkinje layer

18. CEREBELLUM
MOLECULAR
LAYER
GRANULAR
LAYER

19. MOLECULAR LAYER
GRANULAR LAYER
PURKINJE LAYER

21. Cerebrum
• White matter
–Nerve fibers
• Commissural
• Association
• Projection
• Gray matter
–Neurons
–Neuroglia cells

22. Cerebral cortex- type of neurons
• Six type of neurons
• Pyramidal
– Triangular
– Dendrite arises from three
angles
– Axon from the base of cell
– Prominent nucleus and Nissl
substances
– Small sized pyramidal
neuron10-12 micron
– Medium sized neuron 40-50
micron
– Large sized (Betz cells ) > 100
micron

23. • Stellate/granular cells
– Polygonal/triangular
shape
– Dark condensed nucleus
– Dendrites arises all over
– Axon terminate next
layer and goes deeper
• Fusiform cells
– Oriented perpendicular
to the surface
– One dendrites towards
superficially
– One axon towards
deeper layer
STELLATE
F
U
S
I
F
O
R
M

24. • Horizontal cells of Cajal
– Spindle shaped
– Parallel to the surface
– Internuncial type
• Cell of Mortinotti
– Small triangular cells
– Axons goes towards
surface
• Golgi type II
– Process ends close to
cell body
– Local circuit
CAJAL
MORTINOTTI
GOLGI

25. Layers of cerebral cortex
• Outer Molecular layer
– Horizontal cells + Golgi type II
– Tangential nerve fibers from
pyramidal, fusiform and cells of
Mortinotti
• Outer granular layer
– Small pyramidal cells + stellate
cells
– Dendrites end in first layer
– Axons forms association
• Outer pyramidal layer
– Medium and large pyramidal cells
– Axons forms association and
commissural fibers
OM
OP
OG

26. • Inner granular layer
– Packed stellate cells
– Lot of fibers as band-
Outer band of Baillarger
• Inner pyramidal/ganglion
– Large Betz cells
– Axons continues as
projection fibers
– Horizontal fibers forms
inner band of Baillarger
• Multiform layer/fusiform
cells
– Spindle shaped cells
– Granular, fusiform and
stellate type
Outer band
Inner band

27. Molecular layer
Outer granular layer
Outer pyramidal layer
Inner granular layer
Inner pyramidal layer
Pleomorphic layer
Pyramidal neuron

28. Cerebrum-cortex
G