Purpose: In this study, we sought to elucidate changes in the levels of neurotrophin-3 (NT-3) in the rat retina throughout postnatal development and aging.
Methods: We demonstrated NT-3 localization in the retina by immunohistochemistry. Protein and mRNA levels of NT-3 were quantified by enzyme-linked immunosorbant assay and semiquantitative reverse transcriptase-polymerase chain reaction, respectively. NT-3 protein levels were assayed in the various regions of the central nervous system. Age-associated changes in protein and mRNA levels of NT-3 in the retinas were assessed.
Results: NT-3-immunoreactivity localized in the ganglion cell layer, inner nuclear layer, and outer nuclear layer. NT-3 content in the retina was relatively high in the examined regions of the central nervous system. Retinal NT-3 protein levels decreased after eye opening, whereas mRNA levels were constant. Both mRNA and protein levels of NT-3 in the retinas of aged animals remained constant.
Conclusions: Our observations suggest that NT-3 regulation in the retina is independent of increasing visual stimuli after eye opening. Stable expression of NT-3 in the adult retina suggests a possible role in the maintenance of the retinal environment throughout later life.