<p>A: Two serial coronal sections passing through the RTN/PFRG area of a neonatal mouse show SERT mRNA expression (A1) and Cresyl Violet staining (A2). Anatomical limits drawn from A2 Cresyl Violet section have been superimposed on A1 section (dotted line). Note SERT mRNA is expressed in three areas, the median Raphe Magnus (Rm), the para-pyramidal group (ppy) lateral to the pyramid tract (py) and a lateral spot (arrow) located in a medio-ventral position from the facial motor nucleus (n7), as defined from Cresyl Violet staining (in A2). B- 5-HT neurons in the RTN/pFRG area of a neonatal mouse. Note 5-HT neurons in the median raphe magnus (Rm), the parapyramidal group (ppy, doted circle) lateral to the pyramidal tract (py) and the lateral spot (arrow in B1) in the medio-ventral location of the facial nucleus (n7). In B2 and B3, note the superficial location of some 5-HT neurons (arrows). B3 is an enlargement of B1.</p
