Guitarfish possess ipsilateral as well as contralateral retinofugal projections

Abstract

Autoradiographic analysis of the primary retinal projections in the thornback guitarfish reveals both contralateral and ipsilateral projections to diencephalic, pretectal, and tegmental nuclei and the optic tectum. A total of 12 retino-recipient cell groups receive ipsilateral as well as contralateral inputs.

Retinal Projections and Retinal Ganglion Cell Distribution Patterns in a Sturgeon <i>(Acipenser transmontanus),</i> a Non-Teleost Actinopterygian Fish

“…Except for the telencephalic projections, all retinal recipient areas were bilateral, but projections were heavier contralaterally in most target areas. The results coincide basically with those in Acipenser gülden-städti [Repérant et al, 1982], Polypterus palmas, Lepisosteus osseus [Braford and Northcutt, 1983], Lepisosteus platyrhincus [Collin and Northcutt, 1995], Amia calva [Butler and Northcutt, 1992], and Platyrhinoidis triseriata [Northcutt and Wathey, 1980], Lamperta fluviatilis [Vesselkin et al, 1980], Eptatretus burgeri [Kusunoki and Amemiya, 1983], Eptatretus stouti [Wicht and Northcutt, 1990], European Salamandridae [Salamandra salamandra, Triturus cristatus and Triturus alpestris ;Fritzsch, 1980], Ichthyophis kohtaoensis [Himstedt and Manteuffel, 1985], and Bufo marinus [Wye-Dvorak et al, 1992] in that a part of the optic nerve does not decussate at the chiasm, and reaches the ipsilateral target areas. However, Braford and Northcutt [1983] reported that projections to the accessory optic nucleus in Polypterus palmas and Lepisosteus osseus, and to the ventrolateral thalamic nucleus and superficial pretectal nucleus in Lepisosteus osseus are only contralateral.…”

“…We describe the differences by discussing the nomenclature used in previous studies. We also compare the present data with those obtained in four species of chondrichthyans [Nagaprion brevirostris, Graeber and Ebbesson, 1972;Ginglymostoma cirratum, Luiten, 1981a, b; Rhinobatos productus, Ebbesson and Meyer, 1980; Platyrhinoidis triseriata, Northcutt and Wathey, 1980] as well as several teleost species [e.g. Vanegas and Northcutt and Wullimann, 1988;Butler and Saidel, 1991;Ito et al, 1992], lampreys [Vesselkin et al, 1980[Vesselkin et al, , 1984, hagfishes [Kusunoki and Amemiya, 1983;Wicht and Northcutt, 1990], lungfishes [Northcutt, 1977], and amphibians [Fritzsch, 1980;Fritzsch and Himstedt, 1981;Himstedt and Manteuffel, 1985;Uchiyama, 1989;Wye-Dvorak et al, 1992].…”

“…The dorsal hypothalamus lies ventral to the ventral thalamus and medial forebrain bundle rostrally, and also ventral to the medial forebrain bundle and the torus lateralis caudally, extending from the caudal margin of the optic chiasm to the level of the posterior commissure. The caudally elongated retinorecipient area in the dorsal hypothalamus has not been described previously in non-teleost actinopterygians [Acipenser gül-denstädti, Repérant et al, 1982; Polypterus palmas and Lepisosteus osseus, Braford and Northcutt, 1983], chondrichthyans [Negaprion brevirostria, Graeber and Ebbesson, 1972; Platyrhinoidis triseriata, Northcutt and Wathey, 1980; Rhinobatos productus, Ebbesson and Meyer, 1980], or in teleosts [see Vanegas and Ito, 1983;Butler and Saidel, 1991].…”

Binocular Vision and Ipsilateral Retinal Projections in Relation to Eye and Forelimb Coordination

“…VP: IRP are few in the spiny dogfish, Squalus acanthus [Northcutt, 1979], the spotted dogfish, Scyliorhinus canicula [Repérant et al, 1986], and the shark Hemiscyllium plagiosum [Jen et al, 1983]. In the batoid Platyrhinoidis triseriata, numerous IRP have been demonstrated [Northcutt and Wathey, 1980].…”

“…Include four living genera: the dipnoan lungfish (Neoceratodus, Lepidosiren, and Protopterus) and the crossopterygian coelacanth, Latimeria [Nelson, 1984;Carroll, 1988]. VP: In Neoceratodus fosteri, generally considered to be the most primitive of the extant lungfish, IRP has been demonstrated [Moy-Thomas, 1971;Northcutt and Wathey, 1980], while studies in lepidosirenid lungfish have not revealed IRP [Northcutt, 1977;Ward et al, 1995].…”