Click here to close
Hello! We notice that you are using Internet Explorer, which is not supported by Xenbase and may cause the site to display incorrectly.
We suggest using a current version of Chrome,
FireFox, or Safari.
Anat Embryol (Berl)
1988 Jan 01;1774:325-30. doi: 10.1007/bf00315840.
Show Gene links
Show Anatomy links
The ultrastructural organization of the isthmic nucleus in Xenopus.
McCart R
,
Straznicky C
.
???displayArticle.abstract???
The isthmic nucleus (IN) of the frog brain forms a linkage, relaying visual information from one tectum to the other. It receives afferent input from the tectum of the same side and projects bilaterally to both tecta. The ultrastructural features of the tecto-isthmic synaptic connections were studied in young postmetamorphic Xenopus frogs. Most synaptic profiles in the isthmic nucleus have spheroidal vesicles and an asymmetric zone of apposition. Frequently, synaptic glomeruli consisting of up to 8 terminal boutons surrounding a shaft dendrite were observed. The synaptic density in the rostral IN was slightly higher than in the middle or caudal portions. Partial deafferentation by transection of the tecto-isthmic pathway or total deafferentation by removal of the tectum was followed by a widespread degeneration of terminals in the ipsilateral IN. In the former case, the density of synapses in the IN decreased initially by about 64%, and then increased by 30 days after operation to about 50% of the normal synaptic density. After tectal removal, all the terminal boutons in the isthmic neuropil degenerated by 3 days after operation. These studies, along with recent findings, indicate that most, if not all, of the afferent fibres to IN are of tectal origin.
Adams,
Heavy metal intensification of DAB-based HRP reaction product.
1981, Pubmed
Adams,
Heavy metal intensification of DAB-based HRP reaction product.
1981,
Pubmed
Beazley,
The appearance, during development, of responses in the optic tectum following visual stimulation of the ipsilateral eye in Xenopus laevis.
1972,
Pubmed
,
Xenbase
Dann,
The development of connections between the isthmic nucleus and the tectum in Xenopus and Limnodynastes tadpoles.
1982,
Pubmed
,
Xenbase
Gaze,
Binocular interaction in the formation of specific intertectal neuronal connexions.
1970,
Pubmed
Glasser,
The nucleus isthmus as a relay station in the ipsilateral visual projection to the frog's optic tectum.
1978,
Pubmed
Grobstein,
The nucleus isthmi as an intertectal relay for the ipsilateral oculotectal projection in the frog, Rana pipiens.
1983,
Pubmed
Grobstein,
A crossed isthmo-tectal projection in Rana pipiens and its involvement in the ipsilateral visuotectal projection.
1978,
Pubmed
Gruberg,
Anatomy and physiology of a binocular system in the frog Rana pipiens.
1980,
Pubmed
Gruberg,
Topographic projections between the nucleus isthmi and the tectum of the frog Rana pipiens.
1978,
Pubmed
Khalil,
Nucleus isthmi of the frog: structure and tecto-isthmic projection.
1977,
Pubmed
Levine,
An autoradiographic study of the retinal projection in Xenopus laevis with comparisons to Rana.
1980,
Pubmed
,
Xenbase
Straznicky,
The effects of tectal lesion on the survival of isthmic neurones in Xenopus.
1987,
Pubmed
,
Xenbase
Tay,
The development of the nucleus isthmi in Xenopus: an autoradiographic study.
1980,
Pubmed
,
Xenbase
Tóth,
Rental projections in the adult Xenopus laevis: a study with cobalt filling technique.
1980,
Pubmed
,
Xenbase
Udin,
Intertectal neuronal plasticity in Xenopus laevis: persistence despite catecholamine depletion.
1985,
Pubmed
,
Xenbase
Udin,
Plasticity in a central nervous pathway in xenopus: anatomical changes in the isthmotectal projection after larval eye rotation.
1981,
Pubmed
,
Xenbase
Udin,
The development of the nucleus isthmi in Xenopus laevis. I. Cell genesis and the formation of connections with the tectum.
1985,
Pubmed
,
Xenbase
