Distribution within Po of vesicular glutamate transporter-specific immunolabeled axon terminals. a, b, Microphotographs showing in different coronal sections of Po the distribution of terminals marked by immunohistochemistry against the glutamate vesicular transporter type 1 (vGLUT1). Dorsal is to the top and medial to the left. High-magnification details are shown in a1. c–f, Microphotographs showing in different coronal sections of Po the distribution of terminals marked by immunohistochemistry against the glutamate vesicular transporter type 2 (vGLUT2). High-magnification details showing larger vGLUT2 terminals in dorsal domains (d1) and in the border with the ventral posteromedial nucleus (VPM; d2), smaller vGLUT2 terminals in the lateral portion of Po (d3) and domains with almost absence of these terminals in the ventral portion (e1). Arrowheads indicate focal clusters of larger immunopositive puncta. PC: Paracentral nucleus; PF: Parafascicular nucleus. Bregma level in mm is indicated in the upper right corner. Scale bars: 250 µm (a–f) and 25 µm (a1, d1–d3, e1).