Guide to CNS Histology

Cerebellum 40X Magnification – Hematoxylin and Eosin Staining 

Legends:

1.       Medulla of white matter - substansia alba

2.       Granular layer

3.       Purkinje layer

4.       Molecular layer

5.       Meninges – piameter

This is a picture of cerebellum with H&E staining. Cerebellum is divided into medulla and cortex. Medulla is the white matter - substantia alba of cerebellum. Substantia alba consist mostly of myelinated axons and glial cells. Lipids are often washed off during H&E staining. Because of this, some cells and tissue components such as myelin sheath and ground substance are not preserved. The cortex consists of 3 layers – molecular layer, purkinje layer, and molecular layer.

Here we can see the piameter. Piameter is a part of the meninges covering the spinal cord. From the most outer layer is durameter, arachnoidmeter, and piameter.

Cerebellum 100X Magnification – Hematoxylin and Eosin Staining 

Legends:

1.       Cortex of gray matter - substantia grisea

2.       Medulla of white matter - substantia alba

3.       Meninges – piameter

4.       Granular layer

5.       Molecular layer

6.       Purkinje layer

In this picture, we can see the layer much more clearly. Also, the medulla and cortex is highlighted. ________________________________________________________________________________

Cerebellum 400X Magnification- hematoxylin and Eosin Staining 

Legends:

1.       Granular layer

2.       Purkinje cells

3.       Molecular layer

4.       White matter - Substantia alba

This is a high magnification of the cerebellum. The most prominent feature on this slide is the purkinje cells, one of the largest neurons in the human brain. Purkinje cells have dendrite and axons which can be seen depending on the staining used.

Granular layer contains small-size-neuron cell called granule cells with dendrites orienting toward the molecular layer. If the granular layer is looked carefully, there will be some larger cells. These cells are the Golgi cells.

Medulla Spinalis 40X Magnification

Legends:

1. Canalis Centralis
2. Dorsal horn  gray matter 
3. Ventral horn  gray matter 
4. Fissura mediana ventralis  
5. White matter

This is a low magnification of the spinal cord. Spinal cord is part of the nervous system and also consists of gray matter and white matter. Gray matter is located in the central region and divided into ventral and dorsal horn. The outer layer of medulla spinalis is the white matter. In the middle, there is canalis centralis where cerebrospinal fluid flows.

Medulla Spinalis 100X Magnification

Legends:

1.       Canalis centralis

2.       Ependymal cell

3.       Gray matter - Substantia grisea

4.       Sulcus medianus posterior

5.       White matter – Substantia Alba

6.       Fissura mediana ventralis

Here, we can see the Ependymal cells attached to the wall of the central canal. Ependymal cell produces spinal fluid in the central nervous system. They form a single layer of cuboidal to columnar cells that have the morphologic and physiologic characteristics of fluid-transporting cells

Medula Spinalis 400X Magnification

Legends:

1.       Motor neuron

2.     Nucleus

In the ventral horn of medulla spinalis, we can find the motor neuron. Motor neuron transmits action potential to peripheral part of the body. Like other cells, motor neuron also has nucleus.

Legends:

1.       Motor neuron

2.       Axon hillock

3.       Nucleus – prominent nucleolus

4.       Nucleus of neuroglia

5.       Nissl bodies

The axon hillock is characterized by reduced appearance of nissl bodies and surrounding white are that is the myelin sheath lost through staining. Nissl body is actually rough endoplasmic reticulum. In this slide, we can’t see nissl bodies clearly because the cytoplasm looks homogeny. In order to see nissl bodies clearly, a special staining called nissl staining is required.

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 Cerebrum 400X Magnification - Silver Stain

Legends:

1.       Oligodendrocyte

2.       Protoplasmic astrocyte

Oligodendrocyte main functions are to provide support and making myelin sheath in the central nervous system. This function is done by Schwann cell in the peripheral nervous system. Astrocytes are star-shaped glial cells in the brain and spinal cord. They perform many functions, including biochemical support of endothelial cells that form the blood–brain barrier, provision of nutrients to the nervous tissue, maintenance of extracellular ion balance, and a role in the repair and scarring process of the brain and spinal cord following traumatic injuries.

There are 2 types of astrocyte – protoplasmic and fibrous astrocyte. In protoplasmic astrocyte, there are a lot of branches of the processes and the cell body can’t be seen clearly because it accumulated the staining substrate. In fibrous astrocyte, there are long thin unbranched processes. Fibrous astrocyte is mainly found at white matter while protoplasmic astrocyte is mainly found at gray matter.

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Cerebrum 400X Magnification - Hematoxylin and Eosin Stain 

Legends:

1. Neurons
2. Astrocytes
3. Oligodendrocytes 

It is important to be able to identify cells in H&E staining. After all, this is the most used staining in the world. Neurons are easy to find but astrocytes and oligodendrocytes can be tricky. The secret is that oligodendrocytes looks like a perfect fried egg. You can see that oligodendrocytes has white halo and dark nucleus similar to fried eggs that have yellow core and white surrounding.