Histological analysis of the injection site.

<p>A, B – Schematic plotting onto a standard drawing of <i>The rat brain in stereotaxic coordinates </i><a href="http://www.plosone.org/article/info:doi/10.1371/journal.pone.0050361#pone.0050361-Paxinos1" target="_blank">[33]</a> showing the approximate location of the injection cannula tips centered in the dlPAG (A) and the PMd (B). Due to the large number of overlaps, the number of plotted points is lower than the number of subjects actually injected in these regions. C – Bright-field photomicrograph showing Evans blue-stained injection cannula placement in a representative animal that received NMDA 100 pmol into the dlPAG. D – Bright-field photomicrograph showing Evans blue-stained injection cannula placement in a representative animal that received ATE 40 nmol into the PMd region. Abbreviations: DR – dorsal nucleus raphé; III – oculomotor nucleus; PAGdl, dm, l – periaqueductal gray, dorsolateral, dorsomedial, and lateral parts; PMd – dorsal premammillary nucleus; PMv – ventral premammillary nucleus. Scale bars = 250 µm.