Yoshiki Shimizu

Localization of vasoactive intestinal polypeptide and neurotensin immunoreactivities in the avian retina

The distribution of vasoactive intestinal polypeptide (VIP)- and neurotensin (NT)-like immunoreactivities in the chicken retina was investigated by immunohistochemistry. VIP- and NT-positive cells were found throughout the chicken retina. The majority of them were located in the proximal portion of the inner nuclear layer and the processes from these cells directed to the inner plexiform layer where they ramified, suggesting that VIP- and NT-positive cells located in this region probably are amacrine cells.

Demonstration of a substance P-like immunoreactivity in retinal cells of the rat.

The distribution of substance P (SP)-like immunoreactivity in the rat retina was investigated by immunohistochemistry. SP-positive cells were found throughout the retina. The majority of them were located in the proximal portion of the inner nuclear layer and the processes from these cells directed to the inner plexiform layer where they ramified, suggesting that SP-positive cells located in this region probably are amacrine cells. Few SP-positive cells were seen within the ganglion cell layer. They were considered displaced amacrine cells.

Two types of substance P-containing cells and their uneven distribution in the chicken retina: an immunohistochemical analysis with flat-mounts

Substance P-like immunoreactivity (SPI) was investigated in the chicken retina by means of the indirect immunofluorescence method with flat-mounts. SPI cells were located mostly in the peripheral retinal regions, while in the central region, none or only a few cells were seen. Based upon their 3-dimensional profiles, SPI cells can be divided into two types: one type belongs to the stratified amacrine cells of the first sublayer and the other to those of the third to fifth sublayer.

Monoamine accumulating neuron system in the rat retina with special reference to noradrenaline accumulating neurons

Abstract The uptake capacity of the retinal neurons for exogenously administered monoamines was examined in the rat. The present study confirmed the presence of 5,6-dihydroxytryptamine (5,6DHT) accumulating retinal neurons in the rat retina and further disclosed that some retinal cells could accumulate exogenously injected noradrenaline (NA). These NA-labeled cells occupied approximately similar positions in the inner nuclear layer to the 5,6DHT-labeled ones, but the two groups of cells were not identical because simultaneous injections of 5,6DHT and NA demonstrated two types of cells, one having yellow and the other showing green fluorescence, respectively. It should be stressed that these two groups of cells are easily distinguishable from well-known dopamine-containing neurons by their sizes and cell locations. The present study further suggested that the NA-accumulating retinal cells might not contain the NA synthesizing enzyme.

Localization of LH-RH immunoreactivity in the avian retina

The present study demonstrated numerous LH-RH--positive structures in the paddy-bird (padda orizivora) retina. LH-RH-positive cells were seen in the ganglion cell layer (GL), inner plexiform layer (IPL) and inner nuclear layer (INL). Judging from the morphological features, the former two types of cells may belong to the displaced amacrine cells and the latter to the amacrine cells. LH-RH-positive fibers were found in the nerve fiber layer, GL, IPL, INL and outer plexiform layer.

A direct contact of substance P-containing nerve fibers with pupillary sphincter muscle of the rat: An immunohistochemical analysis

Abstract The direct contact between substance P (SP)-containing fibers and pupillary sphincter muscles of the rat was demonstrated at the level of the electron microscope by means of the immunoperoxidase technique. The results suggest a visceromotor function of SP in addition to its presumed sensory function.