Figure 2. Reduced cell survival in Li⁺-treated explants. A-D: Nuclear (A, B) and TUNEL staining (C, D) in E14.5 retinal explants cultured in control (A, C) and Li⁺ (B, D) containing medium for one day. Cell death (indicated by TUNEL+ cells) is increased in the ganglion cell layer (arrow in D) and in the neuroblast layer (arrowhead in D). RGC, retinal ganglion cell layer; RPE, retinal pigment epithelium; NB, neuroblast layer.