Neuronal and glial cell types revealed by NADPH-diaphorase histochemistry in the retina of a teleost fish, the grass goby ( Zosterisessor ophiocephalus , Perciformes, Gobiidae)

Abstract

The grass goby is a mud-burrowing fish with a rich retinal vasculature appropriate to its hypoxic habitat. NADPH-diaphorase histochemistry was performed on retinal sections and wholemounts to reveal cells that contain nitric oxide synthase and so may be presumed to synthesise nitric oxide, a gaseous intercellular messenger with many roles including vasodilation. Structures that were consistently stained by this method included cone ellipsoids, horizontal cells, Müller cells and their processes, large displaced ganglion cells in the inner nuclear layer (identified by their axons), large interstitial ganglion cells in the inner plexiform layer, and capillary endothelial cells. In wholemounts, horizontal cells were seen to form a regular pattern, contacting each other at their dendritic terminals. Some cells in the ganglion cell layer were weakly stained, but stained bipolar and amacrine cells were not seen. The diaphorase-positive large ganglion cells all formed large, sparsely branched dendritic trees, arborizing near the scleral border of the inner plexiform layer. The displaced and interstitial cells seemed to belong to distinct morphological types, the interstitial cells having smaller somata and trees. Analysis of their spatial distributions in one representative retina confirmed this: the displaced cells formed a highly regular mosaic with a mean spacing (nearest-neighbour distance) of 303 microm, whereas the interstitial cells formed a separate mosaic, almost as regular but with a smaller mean spacing of 193 microm, rising to 217 microm in a sample that excluded the area retinae temporalis. Spatial correlogram analysis showed that these two mosaics were spatially independent. Nitric oxide probably has many roles in the retina. The presence of its synthetic enzyme in Müller cells, which communicate with retinal blood vessels, is consistent with a role in the control of retinal blood flow. Its function in large, mosaic-forming retinal ganglion cells is unknown.

Frequency and success of ambush and chase predation in fish assemblages associated with seagrass and bare sediment in an Adriatic lagoon

“…The grass goby's ambush behavior was similar to that reported by Ota et al (1999). Typically, an individual would wait motionless until the lure was within 5-10 cm of its head, and then simultaneously open its mouth, expand its buccal cavity, move toward the lure, and suck the lure completely in.…”

Organization of the nitrergic neuronal system in the primitive bony fishesPolypterus senegalusandErpetoichthys calabaricus(Actinopterygii: Cladistia)

“…However, nitrergic ganglion cells and photoreceptors have been described for the retina of teleosts (Ostholm et al, ; Pottek et al, ; Ota et al, ; Haamedi and Djamgoz, ), amphibians (Nöll et al, ; Kurenni et al, ; Blom et al, ), reptiles (Blute et al, ), birds (Fischer and Stell, ; Wilson et al, ; Tekmen‐Clark and Gleason, ), and mammals (Blom et al, ), where NOS‐ir photoreceptors have not been detected. In addition, nitrergic bipolar cells have been reported for chondrichthyes (Shiells and Falk, ), amphibians (Nöll et al, ; Kurenni et al, ; Blom et al, ), and reptiles (Cao and Eldred, ), whereas horizontal nitrergic cells have been described only for teleosts (Ota et al, ; Haamedi and Djamgoz, ) and reptiles (Haverkamp and Eldred, ; Cuenca et al, ). This increased diversity of nitrergic retinal types observed in more evolved groups of vertebrates could be related to new functions of NO in the retina such as light‐adaptive changes (Greenstreet and Djamgoz, ; Djamgoz et al, ; Angotzi et al, ; Sato et al, ) or circadian effects in photoreceptor activity (Ko et al, ).…”

Retinal ganglion cells with NADPH‐diaphorase activity in the chick form a regular mosaic with a strong dorsoventral asymmetry that can be modelled by a minimal spacing rule

“…(1997); salamander: Kurenni et al . (1995); goldfish: Villani & Guarnieri (1996), grass goby: Ota et al . (1999)].…”