Transgenic approaches to opening up new fields of vasopressin and oxytocin research

Abstract

The hypothalamic-neurohypophyseal system (HNS) is well known as a representative/typical neuroendocrine system, and its characteristics have been investigated using various modern techniques in the fields of morphology, electrophysiology, molecular/genetic technology and computational modelling. [1][2][3][4][5] Rge HNS consists of arginine vasopressin (AVP)-and oxytocin (OXT)-producing magnocellular neurosecretory cells (MNCs) localized in the hypothalamic paraventricular (PVN) and supraoptic nuclei (SON) that project their axon terminals to the posterior pituitary, and secrete AVP and OXT into the systemic circulation. 6 Their physiological actions, such as vasoconstriction/antidiuretic effects, adrenocorticotropic hormone release and uterine contraction/milk ejection, are mediated by specific receptors (V1a, V1b, V2 and OTR) 7 and are characterized pharmacologically by specific agonists and antagonists. 8 In this review, we summarize recent studies related to the transgenic rats that we have generated, which express exogenous genes in AVP-and OXT-producing MNCs. 1.1 | Visualization of AVP and OXT MNCs: AVPenhanced green fluorescent protein (eGFP) and OXT-monomeric red fluorescent protein 1 (mRFP1) transgenic rats AVP-and OXT-producing MNCs are localized in the magnocellular divisions of the PVN and the SON and have few morphological