Oxytocin-immunoreactive projections onto medullary adrenaline neurons

With the use of two-color immunoperoxidase staining, oxytocin-like immunoreactive (OLI) processes have been observed along the surface of phenylethanolamine N-methyl transferase-like immunoreactive (PNMTLI) cells in the ventrolateral and dorsomedial medulla of the rat. OLI boutons were also observed on PNMTLI cells retrogradely labeled with HRP injected into the rostral thoracic spinal cord. The close spatial relationships between OLI processes and PNMTLI cells argues for a functional connection which could provide for direct hypothalamic control of medullary adrenaline cells involved in cardiovascular regulation.