Cerebellum histology

Gross anatomy

The cerebellum is located in the posterior cranial fossa and lies dorsal to the pons and medulla, from which it is separated by the fourth ventricle. There are 2 major  parts to the cerebellum, the cerebellar deep nuclei and the cerebellar cortex.

Output from the cerebellum originates solely in the deep nuclei, where almost all of the neurons of the cerebellum reside. The cerebellum is divided into three subdivisions by two fissures that travel mediolaterally. The flocculonodular lobe is separated from the corpus cerebelli by the posterolateral fissure, while the primary fissure divides the corpus cerebelli into the anterior and posterior lobe.

The cerebellum can also be divided sagittally. Located along the midsagittal plane of the cerebellum in the cortico-nuclear zone is the vermis. The intermediate zone lies directly lateral to the vermis, while the lateral hemispheres lie lateral to the intermediate zone. The two hemispheres have a deeply folded appearance.

As previously mentioned, all outgoing motor signals from the cerebellum originate in the deep nuclei and the nearby vestibular nuclei. The 4 cerebellar deep nuclei include:

• the fastigial
• the emboliform
• the globose
• the dentate nuclei

Three distinct fiber bundles carry all signals into and out of the cerebellum, these include the superior, middle and inferior cerebellar peduncles.

For more details about the anatomy of the cerebellum, take a look below:

Histology

After slicing the cerebellum, it bears a similar resemblance to a cauliflower. This is due to the stemmed appearance of the white matter coated by the outer grey matter of the cortex. When viewing a histological section of cerebellar tissue under the microscope, the lobulations and folia of the cerebellum are immediately evident.

These folia are the leaflike gyri of the cerebellar cortex. The extensive vascular supply will also be evident, as a high blood flow is required to meet the demands of the cerebellum’s neural activity. The pia mater, the innermost layer of the meninges, which covers and protects the cerebellum is also likely to appear surrounding the perimeter of this structure in a stained section.

Embryology

The neural plate, derived from the thickening of ectodermal tissue, is the precursor for all components of the central nervous system. Through a process called neurulation the neural plate folds during the fourth week of gestation to become the neural tube. The rostral portion of the neural tube divides into the prosencephalon (forebrain), mesencephalon (midbrain) and rhombencephalon (hindbrain). The rhombencephalon further divides into the metencephalon and myelencephalon. The cerebellum is derived from the dorsal part of the metencephalon, specifically the alar plate, and the neural folds.

Did you know that you can use our anatomy quiz questions to learn about the cerebellum from scratch OR to test what you already know? 

Neurons found in the cerebellum are derived from two germinal zones; the ventricular zone and the rhombic lip. The ventricular zone is the neuroepithelium of the alar plate which later develops into the roof of the fourth ventricle. Purkinje cells, Golgi cells, stellate cells, basket cells and candelabrum cells are just some of the neurons derived from this particular zone.  

Neurons derived from the rhombic lip include large neurons of the cerebellar nuclei, unipolar brush cells and granule cells.

These 2 groups of neurons are distinguishable by the neurotransmitter they release. Neurons from the ventricular zone are inhibitory GABAergic neurons, while those from the rhombic lip are excitatory glutamatergic.