The area pretectalis is located in the diencephalon.
Anatomy
The area pretectalis lies at the level of the posterior commissure, immediately rostral to the superior colliculi. The area pretectalis can be subdivided into various cell groups, the so-called pretectal nuclei, which have connections with the visual system. The nuclei have different designations in the literature; a common classification comprises the nucleus of the optic tract, the anterior pretectal nucleus, the olivary pretectal nucleus, and the posterior pretectal nucleus.
Afferents
The most important afferents to the area pretectalis originate from the retina and terminate predominantly contralaterally in the nucleus of the optic tract and the olivary pretectal nucleus. Additional afferents to the pretectal nuclei arise from specific visual association areas of the cerebral cortex, the ventral lateral geniculate body, and the superior colliculus.
Efferents
The efferents of the area pretectalis are partly reciprocal to the afferents. Efferents to the lateral geniculate body, superior colliculus, interstitial nucleus of Cajal, the ocular motor nuclei including the Edinger-Westphal nucleus, and the olive are particularly prominent.
Functional significance
The area pretectalis plays an important role as a relay station in the pathway of the pupillary light reflex. In particular, the olivary pretectal nucleus projects bilaterally to specific portions of the parasympathetic oculomotor nucleus, with the crossed fibers passing through the posterior commissure.
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