Connections of the Optic Tectum in the Carp (

University of Groningen Afferent and Efferent Connections of the Optic Tectum in the Carp (Cyprinus carpio L.) Luiten, P.G.M

Evidence for shifting connections during development of the chick retinotectal projection.

The pattern in which optic axons invade the tectum and begin synaptogenesis was studied in the chick. The anterogradely transported marker, horseradish peroxidase, was injected into one eye of embryos between 5 and 16 days of development (E5 to E16). This labeled the optic axons in the brain. The first retinal axons arrived in the most superficial lamina of the tectum on E6. They entered the te...

Organization of the torus longitudinalis in the rainbow trout (Oncorhynchus mykiss): an immunohistochemical study of the GABAergic system and a DiI tract-tracing study.

The torus longitudinalis (TL) is a tectum-associated structure of actinopterygian fishes. The organization of the TL of rainbow trout was studied with Nissl staining, Golgi methods, immunocytochemistry with antibodies to gamma-aminobutyric acid (GABA), glutamic acid decarboxylase (GAD), and the GABA(A) receptor subunits delta and beta2/beta 3, and with tract tracing methods. Two types of neuron...

Retinal fibers alter tectal positional markers during the expansion of the retinal projection in goldfish.

Although widely accepted, the theory, tha t neurones carry immutable cytochemical markers which specify their synaptic connections, is not consistent with plastic reorganizations. Half retinal fish were therefore tested for changed markers following expansion. Optic nerve crush at the time of the half retinal ablation resulted in regeneration of a normal, restricted projection; but nerve crush ...

Redistribution of visual projections in altered optic tecta of adult goldfish.

The retinotectal connections formed in adult goldfish after removal of the rostro-caudal strip of dorsal tectum were mapped electrophysiologically. Initial maps recorded 1 month after surgery revealed visual scotoma corresponding to the ablated tectum. Subsequent maps recorded 4-5 months after the operation showed that the entire visual field redistributed appropriately over the remaining tectu...