Gene expression of nicotinic acetylcholine receptor subunits in the chick retina and central visual areas

Academic Article

Abstract

  • Purpose. Several subunits of the nicotinic acetylcholine receptors (nAChRs) have been characterized in the past few years, and their distribution has been studied by means of immunohistochemical and radioactive in situ hybridization methods. In this study we sought to investigate the distribution of several subunits of the nAChRs in the retina and visual system of the chick using a high resolution nonradioactive in situ hybridization protocol. Methods. cRNA probes labeled with digoxigenin and directed against the α4, α7, α8 and β2 subunits of the nAChRs were applied to cryostat sections of the retina and microtome sections of the chick brain. Hybridization was detected with an antibody against digoxigenin labeled with alkaline phosphatase, and sense sequences were used as controls. Results. In the retina, nAChR transcripts were found in the ganglion cell layer and in one to three populations of cells in the inner nuclear layer, according to the tested probe. In the brain, all four subunits were found in the optic tectum, with a differential distribution across tectal layers. In other visual areas, nAChR subunits occur in varying combinations, e.g., β2 and α7 in the ventral geniculate nucleus, β2 and α7 in the pretectal lentiform nucleus, α4 and α7 in the isthmo-optic nucleus, α4 in the suprachiasmatic nucleus and the ventrolateral thalamus, and α4, α7 and β2 in the lateral spiriform nucleus. Conclusions. These results indicate that nAChR subunits exhibit a differential, partially overlapping, distribution in the retina and brain of the chick and that the non-radioactive in situ hybridization might provide a powerful tool to analyze the distribution of these proteins in the nervous system.
  • Author List

  • Lohmann THO; Britto LRG; Anand R; Lindstrom J; Karten HJ; Keyser KT; Hamassaki-Britto DE
  • Volume

  • 37
  • Issue

  • 3