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Updated: Aug 10, 2026
Immunohistochemical and Calcium Imaging Methods in Wholemount Rat Retina
Published on: October 13, 2014
Calbindin-D 28 kD and parvalbumin in the horizontal cells of rat retina during development
M Oguni1, T Setogawa, H Shinohara
1Department of Ophthalmology, Shimane Medical University, Izumo, Japan. oguni@shimane-med.ac.jp
Insights
Parvalbumin (PV) appears at birth in developing rat retinal horizontal cells, while Calbindin-D 28K (CaD) emerges later, suggesting distinct roles in cell maturation and function.
Area of Science:
- Neuroscience
- Developmental Biology
- Ophthalmology
Background:
- Calbindin-D 28K (CaD) and parvalbumin (PV) are calcium-binding proteins crucial for intraneural calcium buffering in the central nervous system.
- Previous research indicated PV expression at birth in developing retinal horizontal cells.
- The developmental appearance of CaD in these cells remained unclear.
Purpose of the Study:
- To investigate the developmental timeline of CaD and PV expression in rat retinal horizontal cells.
- To correlate the appearance of these calcium-binding proteins with horizontal cell differentiation and maturation.
Main Methods:
- Ultrastructural analysis and immunohistochemistry were employed on rat retinas.
- Samples were collected from postnatal day 0 (P0) to P50.
- The study focused on the distribution of CaD and PV in relation to horizontal cell development.
Main Results:
- Horizontal cells differentiated early postnatally, nearing maturity around P10-P12.
- PV was detected at P0 and subsequently in various retinal cells, including horizontal cells by P7.
- CaD was first observed at P7, with faint expression in horizontal cells by P10, gradually increasing by P15.
Conclusions:
- PV appears in horizontal cells upon their initial ultrastructural distinction.
- CaD emerges as horizontal cells develop structures for endocytosis and synaptic transmission.
- Both PV and CaD may serve as valuable morphological and functional markers for retinal horizontal cells, respectively.
Purpose:
Calbindin-D 28K (CaD) and parvalbumin (PV) are calcium-binding proteins thought to act as an intraneural calcium ion buffering system in the central nervous system. We previously reported that PV appears at birth in some cells in the outer portion of the nuclear layer of the retina that can differentiate into horizontal cells. CaD is also distributed in horizontal cells; however, it is not clear at which developmental stage CaD appears.
Methods:
The development of horizontal cells and the distribution of CaD and PV was examined ultrastructurally and immunohistochemically in rat retinas from birth (P0) to postnatal day 50 (P50).
Results:
Our ultrastructural data showed clear differentiation of horizontal cells from other retinal cells in the early postnatal days. These cells became nearly mature around P10 to P12. PV appeared in the outer nuclear layer at birth (P0) and, by P7, was observed in the ganglion cell layer, amacrine cells, and horizontal cells. CaD-immunoreactive cells, however, were not seen in any portions of the retina until P7. At P10, CaD-immunoreactivity was faintly observed in horizontal cells, and its immunoreactivity gradually increased in the horizontal cells from P10 to P15 when the eyes of the rats opened. CaD was not found in the ganglion cell layer or in amacrine cells at any period examined.
Conclusion:
In the horizontal cells, PV appeared when they were ultrastructurally distinguished from other retinal cells, while CaD appeared when they already had some structure for endocytosis and synaptic transmission, suggesting that PV and CaD may be good morphological and functional markers for horizontal cells, respectively.
