Gray and white matter, cerebellar cortex, meninges !
- Tissue
How the brain and spinal cord look under the microscope: gray matter with cell bodies, white matter with myelinated tracts, wrapped in three meninges.
Updated 2026-11-01
See it in 3D: Cerebellum · White matter · Grey matter of the cord · Spinal cord · Dura mater
What it is
Central nervous tissue has almost no connective tissue: neurons and glia are held together by glial processes. Gray matter holds neuron cell bodies, dendrites and synapses (the neuropil); white matter holds myelinated axon tracts. In the brain the gray matter is outside (cortex) with deep nuclei inside; in the spinal cord it is inside, in an H or butterfly shape. Three meninges and the cerebrospinal fluid protect it.
Key facts
- Blood–brain barrier: tight junctions between continuous endothelial cells, plus their basement membrane and astrocyte foot processes.
- Choroid plexus: capillaries covered by a cuboidal ependymal epithelium that secretes CSF.
- CSF is absorbed into the venous sinuses through arachnoid granulations.
- Epidural space exists naturally only in the spinal canal; in the skull the dura is fused to the bone.
Structure
- Cerebral cortex: six layers of neocortex; large pyramidal neurons (largest in the motor cortex, Betz cells) send axons into the white matter.
- Cerebellar cortex: an outer pale molecular layer with few cells; a single row of large flask-shaped Purkinje cells; an inner granular layer densely packed with small dark granule cells; white matter at the core of each folium.
- Spinal cord: central gray H with large multipolar motor neurons in the anterior horns, smaller neurons in the posterior horns, and lateral horns in thoracic and upper lumbar segments; white matter columns around it; ependyma lines the central canal.
- White matter on H&E: pink, finely fibrillar tissue with few neuron cell bodies and rows of oligodendrocyte nuclei; dark with Luxol fast blue.
- Meninges: dura mater (tough dense collagen), arachnoid (thin layer with trabeculae and the CSF-filled subarachnoid space) and pia mater (delicate layer on the surface, following every sulcus).
Gray vs white matter
| Feature | Gray matter | White matter |
|---|---|---|
| Contains | Neuron cell bodies, dendrites, synapses, unmyelinated axons, glia | Myelinated axon tracts, oligodendrocytes, astrocytes |
| Brain | Outside (cortex) and deep nuclei (basal ganglia, thalamus) | Inside (corona radiata, internal capsule, corpus callosum) |
| Spinal cord | Inside (H-shaped horns) | Outside (posterior, lateral and anterior columns) |
| Groups of cell bodies / axons | Nucleus (in the PNS: ganglion) | Tract (in the PNS: nerve) |
Clinical notes
- Multiple sclerosis: plaques of lost myelin in white matter, typically around the lateral ventricles, in the optic nerves, brainstem and spinal cord.
- Bacterial meningitis: neutrophils fill the subarachnoid space.
- Amyotrophic lateral sclerosis destroys motor neurons of the anterior horn and motor cortex.
- Cerebellar Purkinje cells are among the first neurons damaged by alcohol and by lack of oxygen.
Test yourself
Think of the answer, then tap the question to see it.
What are the three layers of the cerebellar cortex from the surface inward?
The molecular layer, the Purkinje cell layer (a single row of large neurons) and the granular layer packed with small granule cells.
Where is the gray matter in the spinal cord compared with the brain?
In the spinal cord the gray matter is central, in an H shape, with white matter outside; in the brain the cortex is gray on the outside with white matter inside.
Between which two meninges does cerebrospinal fluid circulate?
Between the arachnoid and the pia mater, in the subarachnoid space.
Which structures make up the blood–brain barrier?
Tight junctions between non-fenestrated capillary endothelial cells, their basement membrane and the foot processes of astrocytes.
See it in 3D
The structures of Durgical's 3D anatomy where it is found.
Related
- The neuron and synapse
- Glial cells: astrocytes, oligodendrocytes, microglia, Schwann cells
- Nerve injury and regeneration (Wallerian degeneration)
- Peripheral nerve: endoneurium, perineurium, epineurium; myelin
Related conditions
Educational content on normal microscopic structure and its clinical relevance; no substitute for studying slides or for a health professional's advice.
Sources: 12.1 Basic Structure and Function of the Nervous System (OpenStax, 2022); 13.2 The Central Nervous System (OpenStax, 2022); 13.3 Circulation and the Central Nervous System (OpenStax, 2022); Multiple Sclerosis (MedlinePlus, U.S. National Library of Medicine, 2025).
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Representative model, for educational purposes only.