Perlia's nucleus, also known as nucleus of Perlia and abbreviated as NP, is a spindle-shaped

nucleus Nucleus (: nuclei) is a Latin word for the seed inside a fruit. It most often refers to: *Atomic nucleus, the very dense central region of an atom *Cell nucleus, a central organelle of a eukaryotic cell, containing most of the cell's DNA Nucleu ...

located in the

mesencephalon The midbrain or mesencephalon is the uppermost portion of the brainstem connecting the diencephalon and cerebrum with the pons. It consists of the cerebral peduncles, tegmentum, and tectum. It is functionally associated with vision, hearing, mo ...

, a subdivision of the Edinger-Westphal nucleus situated between the right and left oculomotor nuclei. It is implicated in

parasympathetic The parasympathetic nervous system (PSNS) is one of the three divisions of the autonomic nervous system, the others being the sympathetic nervous system and the enteric nervous system. The autonomic nervous system is responsible for regulat ...

oculomotor The oculomotor nerve, also known as the third cranial nerve, cranial nerve III, or simply CN III, is a cranial nerve that enters the orbit through the superior orbital fissure and innervates extraocular muscles that enable most movements of ...

functions, possibly including input to the

iris Iris most often refers to: *Iris (anatomy), part of the eye * Iris (color), an ambiguous color term *Iris (mythology), a Greek goddess * ''Iris'' (plant), a genus of flowering plants * Iris (given name), a feminine given name, and a list of peopl ...

and ciliary. Perlia's nucleus is believed to be a characteristic found exclusively in animals capable of

binocular vision Binocular vision is seeing with two eyes. The Field_of_view, field of view that can be surveyed with two eyes is greater than with one eye. To the extent that the visual fields of the two eyes overlap, #Depth, binocular depth can be perceived. Th ...

. Moreover, it might be an exclusive characteristic of humans, as indicated by a systematic study of monkey brains, where only 9% exhibited a clear midline group, potentially corresponding to the NP. In 1891, Perlia's nucleus was identified as a central mediator for the convergent movement of the eyes based on clinical findings in ophthalmospegias. It has also recently been attributed an important role in the upward movement or gaze of the eyes.

Structure

Histological Properties

This spindle-shaped nucleus is formed by groups of cholinergic motor neurons. It has

multipolar cells A multipolar neuron is a type of neuron that possesses a single axon and many dendrites (and dendritic branches), allowing for the integration of a great deal of information from other neurons. These processes are projections from the neuron cell ...

in its lower part but bipolar club and spindle-shaped cells are more common in its upper part.

Vegetative cells Vegetative describes vegetation. Vegetative may also refer to: *Vegetative reproduction, a type of asexual reproduction for plants *Persistent vegetative state, a condition of people with severe brain damage *Plant community A plant community is ...

similar to those found in the chief nucleus have also been observed. Cells in the NP are arranged in parallel lines that are ventro-dorsally oriented. Those located in its ventral part have been described as being histologically similar to those in the chief nucleus.

Clinical importance

Eponym

The nucleus is named after german physician and ophtalmologist

Richard Perlia Richard is a male given name. It originates, via Old French, from Old Frankish and is a compound of the words descending from Proto-Germanic language">Proto-Germanic ''*rīk-'' 'ruler, leader, king' and ''*hardu-'' 'strong, brave, hardy', and ...

, who first described its existence in 1889.

References

Midbrain Cranial nerve nuclei Oculomotor nerve {{neuroanatomy-stub

Structure

Histological Properties

Clinical importance

Eponym

See also

References