CNS Sequence

CNS Histology

March 10, 2008

S.K. Kim / J.M. Velkey

Spinal cord & peripheral

ganglia

Dorsal horns: InterneuronsVentral horns: Somatic motor neurons Lateral horns: • Sympathetic visceral motor neurons• Parasympathetic (S2-4) VM neurons

DRG: Sensory (pseudounipolar) neurons

Autonomic ganglia: Post ganglionic neurons with unmyelinated axons.

•Sympathetic: paravertebral & preaortic (celiac, superior mesenteric, etc.) ganglia•Parasympathetic: in organ walls

#65 Spinal cord and DRG#65 Spinal cord and DRG

Ventral Ventral hornhorn

Lateral hornLateral horn

Dorsal Dorsal hornhorn

Dorsal root Dorsal root ganglion (DRG)ganglion (DRG)

Motor neurons, glial cells and neuropil

Glial cells

Neuropil

Dorsal root ganglion

Motor and Sensory Neurons(Multipolar) (Pseudounipolar)

DHDH

DCDC

VHVH

LHLH

DH = dorsal hornDC = dorsal nucleus of Clarke

- thoracic spinal cord

LH = lateral hornVH = ventral horn

66a Spinal Cord (ventral horn motor neurons)

Thoracic cord lateral horn: preganglionic sympathetic neurons of intermediolateral cell column

Thoracic cord lateral horn: spinocerebellar neurons of Clarke’s nucleus (relay proprioceptive input up to cerebellar cortex:

e.g. from muscle spindle DRG spinocerebellar neuron cerebellum)

Thoracic cord: dorsal horn neurons (interneurons) short projections to other neurons at same level or nearby spinal level

Cerebrum

Sulcus (sulci) Gyrus (gyri)

Cerebellum

Pons Medulla oblongata

3rd ventricle

4th ventricle

Brain

Cerebrum and Cerebellum

Cerebellum Cerebrum

W W

CC

C

M

C: Cortex of gray matter W: White

matter

W/M = White matter of cerebellum also called “medulla”

#77 Cerebellum

Cortex

White matter

Slide 77a – luxol blue

white

mat

ter

cortex (gray matter)

#77 Cerebellum

WMWM

GLGL

MLML

PCPC

#76b Cerebrum – tol. blue & eosin

#76

Ross and Pawlina, p.311

Cereb

ral cortex

Layer III Layer III pyramidal pyramidal

cellscells

Layer V Layer V pyramidal pyramidal

cellscells

#NP004N Hippocampal regionCA: Cornus ammonis

CA1

CA3

CA2

Dentate Dentate gyrusgyrus

Hippocampus

CA4 (hilus)

choroid plexus

“typical” ependymal

cells (columnar, lining cells)

ependymal cells of choroid plexus (cuboidal, eosinophilic: produce CSF)

3 layers of Hippocampal region (CA1-CA3)

Molecular Molecular

layerlayer

Pyramidal cell

Pyramidal cell

layerlayer

Polymorphic

layer

Pyramidal cells

3 layers of Dentate gyrus

Molecular Molecular layerlayer

Granule cell layer

Granule cell layer (neurons)(neurons)

Polymorphic layerPolymorphic layer (interneurons and granule cell axons)

Molecular layer (dendrites of granule cells)

Cerebellum – H&E Cerebrum – TB&E

CC

W

W

Purkinje cells (neurons)

Layer V Layer V Pyramidal Pyramidal cells cells (neurons)(neurons)

C: Cortex of gray matter W: White matter

#77 Purkinje neurons #76b Pyramidal neurons

#74 Sympathetic ganglion cells

#75 Parasympathetic ganglion cells(in Seminal vesicle)

Sensory and Autonomic Neurons(Parasympathetic – e.g. from vaginal wall)(DRG)