Where are the cell bodies of Purkinje cells located?

In a row between the molecular and granular layers

In the molecular layer just beneath the pia

Scattered throughout the granular layer

Where do climbing fibres originate?

From the dorsal horn of the spinal cord

What stains blue with Fast Blue?

The myelin sheaths in the white matter

The Nissl substance of Purkinje cells

The dendrites in the molecular layer

No. 36 Nervous tissue

Purkinje cells

Cerebellum · Fast Blue / H&E

Start quiz

Cerebellar cortex, H&E/Klüver, overview: white matter, granular layer, Purkinje cell row, molecular layer — Overview Cerebellar cortex in an H&E/Klüver-type stain: bluish white matter at the upper left, then the dark granular layer, a row of Purkinje cells and the pink molecular layer. On the right, a cleft between two folia. Micrograph: © AnatomyProf

Labels

Labelled structures

Purkinje cells are the largest neurons of the cerebellar cortex and its only efferent neurons. Their pear-shaped cell bodies form a single row at the boundary between the cell-poor molecular layer and the cell-rich granular layer. A huge dendritic tree branches like an espalier in one plane, perpendicular to the long axis of the folium, almost up to the surface.

The images show cerebellar cortex stained with Fast Blue (myelin blue, nuclei and Nissl substance violet) and with an H&E or Klüver-Barrera-type stain. The three-layered cortex is visible even at overview magnification; at high magnification you can see the soma, the nucleus with its nucleolus and the main dendritic trunk.

How to recognise it

Three-layered cortex: pale molecular layer, dark granular layer, a row of cells in between
Large, pear-shaped cell bodies in a single row (Purkinje cell layer)
Thick dendritic trunk running into the molecular layer towards the surface
Large, pale nucleus with a prominent nucleolus
Granular layer of densely packed, small, round nuclei
Leaf-like folds (folia) with central white matter

Structures to find

Molecular layer
Purkinje cell layer (ganglionic layer)
Granular layer
White matter
Soma (perikaryon) of a Purkinje cell
Nucleus with nucleolus
Dendritic tree with main trunk

Structure

The cerebellar cortex (cortex cerebelli) has the same three layers everywhere:

Molecular layer (outer): few cells, many fibres; contains the dendritic trees of Purkinje cells, the parallel fibres of granule cells and stellate and basket cells.
Purkinje cell layer (ganglionic layer): a single row of large Purkinje cell bodies with Bergmann glial cells in between.
Granular layer (inner): densely packed, small, round nuclei of granule cells, plus Golgi cells and nucleus-free islands (cerebellar glomeruli).

Beneath lies the white matter with myelinated afferents (mossy and climbing fibres) and the axons of the Purkinje cells.

Function

Purkinje cells are GABAergic, i.e. inhibitory, projection neurons. The axon leaves the basal pole of the soma, passes through the granular layer and white matter and ends on the deep cerebellar nuclei (e.g. the dentate nucleus) and the vestibular nuclei. Each Purkinje cell receives two very different excitatory inputs: countless parallel fibres from granule cells, which are themselves driven by mossy fibres, and a single climbing fibre from the inferior olive that winds up along the dendritic tree. By comparing these signals the cerebellum corrects ongoing movements. It is therefore essential for coordination, balance, muscle tone and motor learning.

Microscopy tips

At low power the cerebellum is recognised by its leaf-like folds (folia): white matter in the centre, a dark band of nuclei around it (granular layer) and a broad, pale outer zone (molecular layer). Then follow the boundary between the granular and molecular layers – this is where the Purkinje cell bodies sit, often spaced apart rather than in a continuous line. At high power look for the large, pale nucleus with a prominent nucleolus and the thick dendritic trunk heading towards the surface. With Fast Blue the white matter is blue. Pitfall: the cerebral cortex has no dense granular band and no single row of cells at a sharp layer boundary; its pyramidal cells are spread over several layers.

Clinical relevance

Purkinje cells are highly sensitive to hypoxia and toxic damage. Chronic alcohol misuse typically causes atrophy of the cerebellar vermis with loss of Purkinje cells and a broad-based ataxic gait. Purkinje cells are also lost in hereditary spinocerebellar ataxias and in paraneoplastic syndromes (e.g. with anti-Yo antibodies). Histologically there are gaps in the Purkinje cell row and an increase in Bergmann glia. Clinically, cerebellar damage presents with ataxia, intention tremor, dysmetria, dysdiadochokinesia and scanning speech.

Slide images

Cerebellar folium, Fast Blue, overview with white matter, granular and molecular layers — **Overview:** Cerebellar folium stained with Fast Blue: blue white matter in the centre, surrounded by the granular layer and the broad molecular layer. Purkinje cells mark the boundary between granular and molecular layers.

Cerebellar cortex, Fast Blue, overview: blue white matter, dark granular layer and pale molecular layer — **Overview:** Cerebellar folium stained with Fast Blue: the blue white matter is surrounded by the dark granular layer and, outside, by the broad, pale molecular layer. Large Purkinje cell bodies lie along the boundary.

Row of Purkinje cells between granular and molecular layers, H&E, medium magnification — **Medium magnification:** Row of Purkinje cells at the boundary between the granular layer (top) and the molecular layer (bottom). The dendritic trunks point into the molecular layer, i.e. towards the surface.

Cerebellum with white matter, granular layer, Purkinje cells and molecular layer, medium magnification — **Medium magnification:** Transition from the bluish white matter (upper left) via the granular layer to the Purkinje cells and the molecular layer (lower right).

Cerebellar cortex, Fast Blue, medium magnification: granular layer, Purkinje cells, molecular layer, pia — **Medium magnification:** Edge of a folium: granular layer on the left, two Purkinje cell bodies at its border, and the cell-poor molecular layer on the right with pia mater and a vessel at the surface.

Cerebellar granular layer with blue white matter, Fast Blue, medium magnification — **Medium magnification:** White-matter core of a folium: the blue strand of white matter is flanked on both sides by the granular layer; the molecular layer follows at the upper left and bottom, with a few Purkinje cell bodies at the upper left.

Purkinje cell with nucleus, nucleolus and branching dendrite, Fast Blue, high magnification — **High magnification:** Purkinje cell stained with Fast Blue: pear-shaped soma with a large nucleus and nucleolus, giving rise to a thick dendritic trunk that branches. Densely packed granule cells below.

Purkinje cell above the granular layer, Fast Blue, high magnification — **High magnification:** Purkinje cell with its dendritic trunk ascending into the molecular layer; the granular layer with densely packed round nuclei begins at the bottom edge.

Purkinje cell with dendritic trunk, Fast Blue, high magnification — **High magnification:** Purkinje cell at high magnification: the thick dendritic trunk rises from the soma (lower left) into the molecular layer. Small, round glial nuclei lie alongside.

Cerebellar white matter with blue myelin and glial nuclei, Fast Blue, high magnification — **High magnification:** White matter at high magnification: blue-stained myelinated nerve fibres with scattered glial nuclei (mainly oligodendrocytes). Granule cells border it at the top and lower right.

Test your knowledge

Assign the correct number in the image to each term.

Tap the requested structure in the image.

Multiple-choice questions on structure and function.

Frequently asked questions

Why is the inner layer called the granular layer?

It consists of vast numbers of tiny granule cells whose small, round, dark nuclei are packed so densely that they look like grains at low power. Granule cells are the most numerous neurons in the entire brain.

Where does the axon of a Purkinje cell go?

It arises from the basal pole of the soma, passes through the granular layer and white matter and ends with inhibitory synapses on the deep cerebellar nuclei or vestibular nuclei. Purkinje cells are therefore the sole output of the cerebellar cortex.

How do I tell cerebellar from cerebral cortex on a slide?

The cerebellum shows folia with a dense, dark granular band and a single row of large Purkinje cells along its outer edge. The cerebral cortex looks more uniform, has six poorly demarcated layers and triangular pyramidal cells at various depths.