Spontaneous activity patterns in the developing retina appear important for the functional organization of the visual system. We show here that an absence of early retinal waves in mice lacking the β2 subunit of the nicotinic acetylcholine receptor (nAChR) is associated with both gain and loss of functional organization in the dorsal lateral geniculate nucleus (dLGN). Anatomical studies show normal gross retinotopy in the β2−/− dLGN but suggest reduced topographic precision in the retinogeniculate projection. Physiological recordings reveal normal topography in the dorsoventral visual axis but a lack of fine-scale mapping in the nasotemporal visual plane. In contrast, unlike wild-type mice, on- and off-center cells in the β2−/− dLGN are spatially segregated. The presence of the β2 subunit of the nAChR in the CNS is therefore important for normal functional organization in the retinogeniculate projection.
Present addresses: CNRS UMR 8544, Ecole Normale Supérieure, 46 rue d'Ulm, 75005 Paris, France, and CNRS UPR 1929, Institut de Biologie Physico-Chimique, 13 rue Pierre et Marie Curie, 75005 Paris, France.
