The anatomy of the Göttingen minipig hypothalamus.

The microscopic organization of the Göttingen minipig (sus scrofa) hypothalamus was studied using Nissl stain, acetylcholinesterase histochemistry, and immunohistochemical staining for calretinin, tyrosin hydroxylase, oxytocin, vasopressin, and orexin A. Mediolaterally the minipig hypothalamus can be divided into three cytoarchitectonic distinct longitudinal zones. The periventricular longitudinal zone comprises the supraoptic, paraventricular, median preoptic, anteroventral periventricular, suprachiasmatic and arcuate nuclei. The medial longitudinal zone includes the prominent medial preoptic, ventromedial, dorsomedial and medial mammillary nuclei. Together with the anterior hypothalamic area, they can be further divided into distinct subregions. The dorsal and posterior hypothalamic areas and the retromammillary and lateral mammillary nuclei are cyto- and chemoarchitectonically distinct but cannot be further divided into subregions. The cell sparse, fiber rich lateral longitudinal zone comprises the lateral preoptic and lateral hypothalamic area as well as the perifornical, lateral tuberal and tuberomammillary nuclei. The findings presented here indicate that the cyto- and chemoarchitecture of the Göttingen minipig hypothalamus is comparable to that of rat, landrace pig, monkey, and human and that the Göttingen minipig may be well suited for future, non-primate, large mammal, hypothalamic research.