The suprachiasmatic nucleus in the sheep: retinal projections and cytoarchitectural organization

Autor: M. Caldani, A. Locatelli, Howard M. Cooper, M. C. Viguier-Martinez, A. Tessonneaud
Přispěvatelé: Unité de recherche Physiologie de la reproduction des mammifères domestiques, Nouzilly, Institut National de la Recherche Agronomique (INRA), ProdInra, Migration
Rok vydání: 1994
Předmět:
Male
Retinal Ganglion Cells
[SDV]Life Sciences [q-bio]
Immunoenzyme Techniques
0302 clinical medicine
Image Processing
Computer-Assisted
Amino Acids
Horseradish Peroxidase
ComputingMilieux_MISCELLANEOUS
Brain Mapping
0303 health sciences
Suprachiasmatic nucleus
Cerebrum
Anatomy
Circadian Rhythm
[SDV] Life Sciences [q-bio]
medicine.anatomical_structure
Hypothalamus
Acetylcholinesterase
Nissl body
symbols
Suprachiasmatic Nucleus
hormones
hormone substitutes
and hormone antagonists
Retinohypothalamic tract
endocrine system
Histology
Wheat Germ Agglutinins
Neuropeptide
Nerve Tissue Proteins
[INFO] Computer Science [cs]
Biology
Retina
Pathology and Forensic Medicine
Electron Transport Complex IV
03 medical and health sciences
symbols.namesake
Species Specificity
medicine
Animals
[INFO]Computer Science [cs]
Dominance
Cerebral
030304 developmental biology
Afferent Pathways
Sheep
Neuropeptides
Cell Biology
nervous system
sense organs
Nucleus
030217 neurology & neurosurgery
Zdroj: Cell and Tissue Research
Cell and Tissue Research, Springer Verlag, 1994, 278, pp.65-84
ISSN: 1432-0878
0302-766X
DOI: 10.1007/bf00305779
Popis: The retinal innervation, cytoarchitectural, and immunohistochemical organization of the suprachiasmatic nucleus (SCN) was studied in the domestic sheep. The SCN is a large elongated nucleus extending rostrocaudally for roughly 3 mm in the hypothalamus. The morphology is unusual in that the rostral part of the nucleus extends out of the main mass of the hypothalamus onto the dorsal aspect of the optic chiasm. Following intraocular injection of wheat-germ agglutininhorseradish peroxidase or tritiated amino acids, anterograde label is distributed throughout the SCN. Retinal innervation of the SCN is bilaterally symmetric or predominantly ipsilateral. Quantitative image analysis demonstrates that, although the amount of autoradiographic label is greatest in the ventral and central parts of the nucleus, density varies progressively between different regions. In addition to the SCN, retinal fibers are also seen in the medial preoptic area, the anterior and lateral hypothalamic areas, the dorsomedial hypothalamus, the retrochiasmatic area, and the basal telencephalon. Whereas the SCN can be identified using several techniques, complete delineation of the nucleus requires combined tract tracing, cytoarchitectural, and histochemical criteria. Compared with the surrounding hypothalamic regions, the SCN contains smaller, more densely packed neurons, and is largely devoid of myelinated fibers. Cell soma sizes are smaller in the ventral SCN than in the dorsal or lateral parts, but an obvious regional transition is lacking. Using Nissl, myelin, acetylcholinesterase, and cytochrome oxidase staining, the SCN can be clearly distinguished in the rostral and medial regions, but is less differentiated toward the caudal pole. Immunohistochemical demonstration of several neuropeptides shows that the neurochemical organization of the sheep SCN is heterogeneous, but that it lacks a distinct compartmental organization. Populations of different neuropeptide-containing cells are found throughout the nucleus, although perikarya positive for vasoactive intestinal polypeptide and fibers labeled for methionine-enkephalin are predominant ventrally; neurophysine-immunoreactive cells are more prominent in the dorsal region and toward the caudal pole. The results suggest that the intrinsic organization of the sheep SCN is characterized by gradual regional transitions between different zones.
Databáze: OpenAIRE
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