Fig. 4.

Serotonergic neurons are in close proximity to PYY cell bodies. RMg, Raphe magnus; Rob, Raphe obscures; RPa, raphe pallidus. A: representative IHC image using serotonin (5-HT) antibody on brain stem sections prepared from PYY-Cre;ROSA-EYFP mice, showing close proximity of two neuron groups. Bregma, 6.36 mm. B: high magnification confocal image of the section in A showing close apposition between 5-HT and PYY cell bodies. C: high magnification confocal image of the section in A showing close apposition between 5-HT-ir projections and PYY cell bodies. D: representative confocal image of an EYFP-positive neuron in the Rob nuclei costained with 5-HT antibody. Red, 5-HT immunostaining; green, EYFP; yellow, colocalization.