Retinal horizontal cell is second-order neuron that integrates the information from photoreceptors over large retinal areas, mediating the lateral spread of visual signals to distant retina. The Neurofilament proteins, considered as neuronal markers, have been imunolocalized to mammalian retinal horizontal cess. However, the immunolabeling of Neurofilament in human, has been focused on the studies of visual pathway and large ganglion cells The goal of this study is to see whether human retinal horizontal cells are indeed neuronal nature or glial nature by immunogold labeling for electron microscopy. The sections of 65 year-old human retina showed the expression of Neurofilament by horizontal cells, which confirms the evidence of human retinal horizontal cell as neuronal nature.
Aged ; Ganglion Cysts ; Humans* ; Microscopy, Electron ; Negotiating ; Neurofilament Proteins ; Neurons ; Retina ; Retinal Horizontal Cells* ; Retinaldehyde* ; Visual Pathways

Calcium is one of the most versatile intracellular second messengers, which plays crucial roles in many intracellular signaling pathways. Researches on intracellular calcium distribution, regulation and function are important for our understanding of cellular physiology. In this mini-review, the regulation of intracellular calcium signal in retinal horizontal cells and the relevant physiological functions were introduced based on the experiments carried out in our laboratory. Intracellular calcium dynamics following the activation of AMPA and NMDA receptors were introduced based on our experiments performed on carp retinal horizontal cells using calcium imaging technique and computational methods. An initial peak response was observed in both cases, which indicated an active participation of intracellular calcium store during the calcium dynamics initiated by AMPA/NMDA receptor activation. Intracellular recording experiments indicated that calcium signaling was crucial for the gradual enhancement of the retinal horizontal cell's responsiveness in exposure to repetitive red flashes. Possible roles of intracellular calcium signaling in the regulation of GABA transporter activity were also introduced based on our whole-cell recording experiments performed on isolated carp retinal horizontal cells.
Animals ; Calcium ; metabolism ; Calcium Signaling ; Carps ; Cells, Cultured ; Patch-Clamp Techniques ; Receptors, AMPA ; metabolism ; Receptors, N-Methyl-D-Aspartate ; metabolism ; Retinal Horizontal Cells ; physiology

In the present study, the modulatory effect of AMPA receptors on gamma-aminobutyric acid (GABA) transporter current was investigated on enzymatically isolated horizontal cells of carp retina. The GABA transporter current elicited by 1 mmol/L GABA was decreased immediately after pre-application of AMPA (30 mumol/L or 3 mmol/L) for 50 s. Application of 10 mmol/L BAPTA in intracellular solution inhibited the suppression effect of AMPA on GABA transporter current. The suppression effect induced by co-application of 3 mmol/L AMPA and 3 mmol/L NMDA was similar to that of 3 mmol/L AMPA or 3 mmol/L NMDA alone. These results suggest that the activation of AMPA receptors inhibits GABA transporter-mediated current by affecting intracellular Ca(2+) processes in the retinal horizontal cells, which is identical with the modulatory effect of NMDA receptors on GABA transporters.
Animals ; Carps ; Egtazic Acid ; analogs & derivatives ; pharmacology ; GABA Plasma Membrane Transport Proteins ; metabolism ; Receptors, Ionotropic Glutamate ; metabolism ; Retinal Horizontal Cells ; metabolism ; gamma-Aminobutyric Acid ; pharmacology

The aim of the present study was to investigate the effects of prenatal alcohol exposure (PAE) on the development and cell differentiation of retina in offspring. The mouse model of PAE was made. HE staining and immunofluorescent labeling were carried out to visualize the structure, development and cell differentiation of the retina from postnatal day 0 (P0)-P30 offspring. The results showed that PAE can lead to the retardation of retinal development, the reduction of number of bipolar cells and horizontal cells, the disorder of horizontal cells' polarity, as well as the retinal thickening in a dose-dependent manner. The data suggest that alcohol exposure during pregnancy can lead to the developmental retardation of retina and decreased number of bipolar cells and horizontal cells in the retina of offspring.
Animals ; Cell Differentiation ; drug effects ; Disease Models, Animal ; Ethanol ; adverse effects ; Female ; Male ; Mice ; Pregnancy ; Prenatal Exposure Delayed Effects ; chemically induced ; Retina ; cytology ; drug effects ; Retinal Bipolar Cells ; drug effects ; Retinal Horizontal Cells ; drug effects