Putative cholinergic projections from the nucleus isthmi and the nucleus reticularis mesencephali to the optic tectum in the goldfish (Carassius auratus).

摘要: The nucleus isthmi of fish and amphibians has reciprocal connections with the optic tectum, biochemical studies suggested that it may provide a major cholinergic input to tectum. In goldfish, we have combined immunohistochemical staining for choline acetyltransferase retrograde labeling neurons after tectal injections horseradish peroxidase. Seven received peroxidase injections, brain tissue from these animals was subsequently processed simultaneous visualization acetyltransferase. many dense label obscured reaction product but were colocalized in 54 cells nine nuclei isthmi. somata reticularis mesencephali stained so intensely could not determine whether they labelled also However, large acetyltransferase-immunoreactive axons enough us follow them rostrally; are clustered together until level rostral tectum where two groupings form: one travels into other rostroventrally cross midline enter contralateral diencephalic preoptic area. We conclude therefore project as well goldfish.