Organization of the inner retina following early elimination of the retinal ganglion cell population: Effects on cell numbers and stratification patterns

• Published in: Visual neuroscience 2001-03, Vol.18 (2), p.233-244, Article S0952523801182088
• Main Authors: WILLIAMS, R.R., CUSATO, K., RAVEN, M.A., REESE, B.E.
• Format: Article
• Language: English
• Subjects: Amacrine cell; Amino Acid Transport Systems, Neutral; Animals; Axotomy; Biological and medical sciences; Calbindins; Carrier Proteins - metabolism; Cell Count; Cell Death; Eye and associated structures. Visual pathways and centers. Vision; Female; Ferrets; Fluorescent Antibody Technique, Indirect; Fundamental and applied biological sciences. Psychology; gamma-Aminobutyric Acid - metabolism; Glycine - metabolism; Glycine Plasma Membrane Transport Proteins; Immunoenzyme Techniques; Inner plexiform layer; Neurons - cytology; Neurons - metabolism; Optic nerve; Optic Nerve - surgery; Parvalbumins - metabolism; Pregnancy; Retina - anatomy & histology; Retina - metabolism; Retinal Ganglion Cells - physiology; S100 Calcium Binding Protein G - metabolism; Vertebrates: nervous system and sense organs
• ISSN: 0952-5238; 1469-8714
• DOI: 10.1017/S0952523801182088

The present study has examined the effects of early ganglion cell elimination upon the organization of the inner retina in the ferret. The population of retinal ganglion cells was removed by optic nerve transection on the second postnatal day, and retinas were subsequently studied in adulthood. Numbers of amacrine and bipolar cells were compared in the nerve-transected and nerve-intact retinas of operated ferrets, while stratification patterns within the inner plexiform layer were compared in these and in normal ferret retinas. Early ganglion cell elimination was found to produce a 25% reduction in the population of glycine transporter-immunoreactive amacrine cells, and 18 and 15% reductions in the populations of parvalbumin and calbindin-immunoreactive amacrine cells, respectively. GABAergic amacrine cells were also reduced by 34%. The number of calbindin-immunoreactive displaced amacrine cells, by contrast, had increased in the ganglion cell-depleted retina, being three times their normal number. Other amacrine and bipolar cell types were unaffected. Despite these changes, the stratification patterns associated with these cell types remained largely intact within the inner plexiform layer. The present results demonstrate a class-specific dependency of inner retinal neurons upon the ganglion cell population in early postnatal life, but the ganglion cells do not appear to provide any critical signals for stratification within the inner plexiform layer, at least not after birth. Since they themselves do not produce stratified dendritic arbors until well after birth, the signals for stratification of the bipolar and amacrine cell processes should arise from other sources.