Figure 3.
Representative bright-field photomicrographs of a series of coronal sections with areas of FoxP1 and FoxP2 mRNA expression from film in adult male zebra finch brain are shown next to corresponding Nissl-stained sections. Schematic drawings of the Nissl stains highlight areas of expression. (see Materials and Methods for the specificity and the anatomical designation of mRNA expression patterns). A–D, Side-by-side comparisons of FoxP1 (right) and FoxP2 (left) reveal cortical, striatal, and thalamic regions with distinct, as well as overlapping, expression of the two genes. The inset in A shows adjacent sections hybridized with corresponding sense probes. Note strong FoxP1 expression within area X in B and within HVC in C, two song nuclei. The arrowheads in A point to the region of Bas. Locations of sections in A–D correspond to the level of plates 3, 5, 17–18, and 19 in the canary atlas of Stokes et al. (1974), respectively. C, D, FoxP1 and FoxP2 are additionally expressed in subtelencephalic motor and sensory processing structures. Scale bars, 1 mm.