Retinal Projections in Cyprinid Fishes: A Degeneration and Radioautographic Study

Abstract

The retinal projections of three species of cyprinid fish (Cyprinus macrolepidotus, Cyprinus carpio, Rudlus rutilus) were examined with Nauta and Fink-Heimer methods following enucleation and with radioautography following intraocular injection of [³H]-L-proline. Optic tract axons cross completely in the optic chiasma and are distributed to the hypothalamus (nucleus opticus hypothalamicus pars magnocellularis), the thalamo-pretectal region (11 distinct primary optic centers), and the tectum opticum (stratum fibrosum et griseum superficiale, stratum griseum centrale and stratum album centrale). No accessory optic tract was found. The experimental studies on visual projection of various teleosts are reviewed and discussed.

A GFP-based genetic screen reveals mutations that disrupt the architecture of the zebrafish retinotectal projection

“…Although a DiI tracing study in larval zebrafish made only cursory mention of tectal layers (Burrill and Easter, 1994), our confocal analysis of the Brn3c:mGFP and the Shh:GFP transgenic lines demonstrates that exactly four well-defined retinorecipient layers exist at 6 dpf. In adult teleost species, four major layers of retinal fibers have been described (Reperant and Lemire, 1976;Vanegas and Ito, 1983;von Bartheld and Meyer, 1987), with very similar characteristics to the layers we saw in the larvae. We have therefore adopted the nomenclature developed for the adult structures.…”

Afferent and efferent connections of the cerebellum of the chondrostean Acipenser baeri: A carbocyanine dye (DiI) tracing study

“…In the goldfish, vision‐related pretectal cell groups project to the caudal half of the lateral valvula but not to its rostral part (Yanagihara et al, 1993) and bilateral lesions of the cerebellar valvula or the pretectal area completely abolish the dorsal light response (Yanagihara et al, 1993). As in holosteans and teleosts (Northcutt and Buttler, 1976; Repérant and Lemire, 1976; Finger and Karten, 1978; Ito et al, 1984; Sas and Maler, 1986; Striedter, 1990; Butler and Saidel, 1991), the sturgeon pretectal region containing cerebellopetal neurons receives abundant retinal projections (Repérant et al, 1982; Ito et al, 1999). In teleosts, the paracommissural nucleus likewise receives telencephalic projections, indicating that it relays indirect telencephalocerebellar projections (Ito et al, 1982).…”

Anatomy and function of retinorecipient arborization fields in zebrafish

“…Early, excellently detailed retinal projection studies in cyprinids (common roach Rutilus rutilus and carp, Repérant & Lemire, 1976; common rudd Scardinius erythrophthalmus , Repérant et al, 1976, Peyrichoux et al, 1977) reported in essence the same retinorecipient targets listed above for the zebrafish (the neuroanatomical terms for the rudd are given in parentheses below). Repérant and Lemire (1976) and Repérant et al (1976) described as retinorecipient the PSp (then identified as nucleus geniculatus lateralis) and various additional pretectal nuclei corresponding to the PPd/PCN (centrum opticum commissurae posterioris), the CPN (centrum opticum pretectale dorsale), DAO (centrum opticum pretectale mediale + ventrale), VAO (centrum opticum accessorium), as well as the ventral and dorsal thalamus (centrum opticum dorsolaterale thalami) and the suprachiasmatic and posterior parvocellular preoptic nucleus (centrum opticum hypothalamicum). Interestingly, a VAO and an additional RN corticalis were only described in some predominantly visually guided cypriniforms in which the PSp was furthermore rather large (i.e., folded).…”