Numbers of Retinal Ganglion Cells in Mice with Genetic Defects in Different A1 Adrenoreceptor Subtypes

Abstract

Objective. To perform a comparative study of the numbers of retinal ganglion cells (RGC) in mice with genetic defects affecting different subtypes of α1 adrenoreceptors. Materials and methods. Studies were run on 36 male laboratory mice aged over 18 months with genetic defects affecting one α1 adrenoreceptor subtype (α1a, α1b, α1d). The control group consisted of intact laboratory mice (C57Bl/6NTac) of the same age and sex distribution. An immunofluorescent method was used for differential visualization of cells in retinal wholemount preparations using the Brn3a marker allowing these cells to be counted. Results. Mice with genetic defects of α1b and α1d adrenoreceptors had more and mice with defective α1a adrenoreceptors had fewer RGC than intact mice of the same age and sex. The total numbers of retinal cells in mice of all the study strains were essentially identical. Conclusions. The results obtained here provide evidence that each α1 adrenoreceptor subtype (α1a, α1b, α1d) makes a specific contribution during the process of forming retinal topography.