Putative cholinergic projections from the nucleus isthmi and the nucleus reticularis mesencephali to the optic tectum in the goldfish (Carassius auratus)
Document Type
Article
Abstract
The nucleus isthmi of fish and amphibians has reciprocal connections with the optic tectum, and biochemical studies suggest that it may provide a major cholinergic input to the tectum. In goldfish, we have combined immunohistochemical staining for choline acetyltransferase with retrograde labeling of nucleus isthmi neurons after tectal injections of horseradish peroxidase. Seven fish received tectal horseradish peroxidase injections, and brain tissue from these animals was subsequently processed for the simultaneous visualization of horseradish peroxidase and choline acetyltransferase. In many nucleus isthmi neurons the dense horseradish peroxidase label obscured the choline acetyltransferase reaction product but horseradish peroxidase and choline acetyltransferase were colocalized in 54 cells from nine nuclei isthmi. The somata of nucleus reticularis mesencephali neurons stained so intensely for choline acetyltransferase that we could not determine whether they were labelled also with horseradish peroxidase. However, the large choline acetyltransferase‐immunoreactive axons of nucleus reticularis mesencephali neurons stained intensely enough for us to follow them rostrally; the axons are clustered together until the level of the rostral tectum where two groupings form: one travels into the tectum and the other travels rostroventrally to cross the midline and enter the contralateral diencephalic preoptic area. We conclude therefore that cholinergic neurons project to the optic tectum from the nucleus isthmi as well as nucleus reticularis mesencephali in goldfish. Copyright © 1988 Alan R. Liss, Inc.
Keywords
choline acetyltransferase, horseradish peroxidase, immunohistochemistry, neurotransmitters, retrograde labelling
Publication Date
1-1-1988
Publication Title
Journal of Comparative Neurology
ISSN
00219967
E-ISSN
10969861
Volume
273
Issue
3
First Page
385
Last Page
398
PubMed ID
2463280
Digital Object Identifier (DOI)
10.1002/cne.902730309
Recommended Citation
Zottoli, Steven J.; Rhodes, Kenneth J.; Corrodi, J. Gregory; and Mufson, Elliott J., "Putative cholinergic projections from the nucleus isthmi and the nucleus reticularis mesencephali to the optic tectum in the goldfish (Carassius auratus)" (1988). Translational Neuroscience. 1928.
https://scholar.barrowneuro.org/neurobiology/1928