Figure 1. Digital images of coronal sections of the chick brain through the ventral lateral geniculate nucleus (top) and the lentiform nucleus of the mesencephalon (bottom), taken under rhodamine (a8 and a5) and fluorescein (GABA) microscope filters. The arrows indicate double-labeled neurons and the arrowheads indicate neurons containing only one of the antigens studied. GABA, gamma-aminobutyric acid. Scale bars: 25 µm. Note the greater magnification of the bottom images.