E. Callegari

Peripheral territory and neuropeptides of the trigeminal ganglion neurons centrally projecting through the oculomotor nerve demonstrated by fluorescent retrograde double-labeling combined with immunocytochemistry.

The peripheral territories of sheep trigeminal neurons which send their central process to the brainstem through the oculomotor nerve were investigated by the use of fluorescent tracers in double-labeling experiments. For this purpose Diamidino yellow (DY) injection into the oculomotor nerve was combined with Fast blue (FB) injection either into the extraocular muscles (EOMs), or the cornea, or the superior eyelid. Double-labeled DY + FB cells were found in the ophthalmic region of the trigeminal ganglion in addition to single-labeled DY or FB cells. The DY and DY + FB-labeled trigeminal cells were analysed immunocytochemically for their content of substance P (SP)-, calcitonin gene-related peptide (CGRP)-, and cholecystokinin-8 (CCK-8)-like. All single-labeled DY cells showed SP-, CGRP- or CCK-8-like immunoreactivity. Double-labeled DY + FB neurons innervating the EOMs were immunoreactive for each of the three peptides, whereas double-labeled neurons supplying the cornea were only CGRP-like positive. The findings suggest that, in the sheep, trigeminal neurons which send their process centrally through the oculomotor nerve supply the EOMs, the cornea, and the superior eyelid and contain neuropeptides which are usually associated with pain sensation.

Anatomical relationship between mesencephalic trigeminal nucleus and cerebellum in the duck

Abstract A number of multipolar mesencephalic trigeminal nucleus cells react to cerebelectomy or decortication of the proprioceptive muscle afferent projection area or interruption of the posterior cerebellar peduncle. The cell reaction consists of a great increase in neurofilaments within the perikaryon. The reaction following decortication and interruption of the posterior cerebellar peduncle leads to the conclusion that processes of some multipolar mesencephalic trigeminal nucleus cells reach the cerebellar cortex directly via posterior cerebellar peduncles.

Ultrastructural observations on the tapetum lucidum fibrosum.

The ultrastructural comparison made between the tapetum cellulosum of the cat and the tapetum fibrosum of the sheep has shown that the rods and the collagen fibrils have the same diameters and the same spatial arrangement.

Afferent trigeminal fibres in the oculomotor nerve and their physiological role.

Histological and electrophysiological demonstration of aberrant afferent trigeminal fibers in the oculomotor trunk.

Cerebellar and spinal projections of the coeruleus complex in the duck: A fluorescent retrograde double‐labeling study

The double fluorescent retrograde tracing technique was used to identify, within the coeruleus complex (Co complex) of the duck, the nerve cells projecting to the cerebellar cortex and to the spinal cord. This technique was also used to investigate the possibility that the cerebellar and spinal projections of the Co complex are collaterals of the same axons.