Thyrotrophs are basophilic TSH hormone-producing cells occurring in pars distalis (pd) and pars tuberalis (pt) of the adenohypophysis. These cells are involved in the regulation of thyroid hormones secretion through the hypothalamic-pituitary-thyroid complex. Within the thyrotrope subsets other neuroendocrine peptides are co-localized with TSH hormonesecretogranins/chromogranins, a highly conserved polypeptide termed 7B2, a neuropeptide substance P, neuromedin B, galanin, and calretinin. Based on previously reported data, they may function as local modulators of TSH secretion in an autocrine or a paracrine fashion. However, the precise function of these neuroendocrine peptides in thyrotrophs is yet to be explained.