Figure 1.

Distribution of vasopressin-immunostained fibers through the rostrocaudal extent of amygdala in the rat. Low (A–K) and high power (A_a–K_a) photomicrographs and tracings of arginine-vasopressin (AVP) labeled fibers (A_b–K_b) in coronal sections, illustrating the heterogeneous distribution in the density of AVP fibers among different amygdalar regions. The highest density was found in the MePD region at Bregma level −2.70 mm (panel I, and table). Each of the panels from (A–K) corresponds to a representative example at the bregma level indicated in the table gray boxes. For the semiquantitative analysis in the table, the summed length (calculated with ImageJ) of fibers in a 0.04 mm² area, inside this highest density region was assigned as 100%, regions with summed lengths between 76–100% were assigned as ++++; between 51–75% : +++; between 26–50%: ++ and between 1–25%: +. Anatomical maps and nuclei nomenclature are from the rat atlas of Swanson (2003). CxA, cortico-amygdalar transition zone; AA, anterior amygdala area; Aco, anterior-cortical amygdaloid nucleus; MeA, medial anterior amygdaloid nucleus; BMA, basomedial anterior amygdaloid nucleus; CeA, central nucleus of amygdala; BLA, basolateral amygdala; STIA, stria terminalis intra-amygdaloid division; MePD, medial postero-dorsal amygdaloid nucleus; MePV, medial postero-ventral amygdaloid nucleus; BMP, basomedial posterior amygdaloid nucleus. Scale bars in (A_a–K_a, A_b–K_b) 50 μm, Bregma levels are indicated below each low power photomicrograph. Squared region indicates the 200 μm area used for calculation of summed length for each amygdala region.