Oxytocin and vasopressin immunoreactivity in rabbit hypothalamus during estrus, late pregnancy, and postpartum |
| |
Authors: | Mario Caba Rae Silver Gabriela Gonz lez-Mariscal Angeles Jim nez Carlos Beyer |
| |
Affiliation: | aCentro de Investigatión en Reproducción Animal, CINVESTAV —Universidad Autónoma de Tlaxcala, Apartado Postal 62, Tlaxcala, Tlax 90 000. Mexico bInstituto de Investigaciones Biológicas, Universidad Veracruzana, Xalapa, Ver, México cBarnard College and Columbia University; 3009 Broadway. New York, NY, USA |
| |
Abstract: | Mother rabbits construct an elaborate maternal nest before parturition and display a single, brief, daily nursing bout throughout lactation. These features present a unique model for investigating the relevance of changes in neuroendocrine secretion associated with pregnancy and parturition for the regulation of maternal behavior. In the present study we analyzed changes in the location, somal size, and number of oxytocin (OT)and arginine vasopressin (AVP)-immunoreactive (IR) neurons in the hypothalamus of rabbits in estrus, late pregnancy (day 29), and postpartum day 1. From estrus to late pregnancy, the number of OT-IR neurons increased in the scattered cell groups located in the lateral hypothalamic area (LHA), but not in the magnocellular nuclei, i.e., paraventricular nucleus (PVN) and supraoptic nucleus (SON). On postpartum day 1 the increase in the number of OT-IR neurons was sustained in the LHA and became apparent also in the main body of the PVN, in which the number of OT-IR neurons doubled. Increases in the somal size of OT-IR cells were seen in all three nuclei only on postpartum day 1. No OT-IR cells were found in the suprachiasmatic nucleus (SCN). From late pregnancy and into postpartum day 1 increases in the somal size of AVP-IR neurons were detected in the PVN, SON, and LHA but not in the SCN. The number of AVP-IR neurons increased between late pregnancy and postpartum day 1 in the SON only. The changes observed in OT and AVP expression in specific hypothalamic nuclei may be related to specific somatic and behavioral events occurring around the time of parturition, e.g., nest-building, maintenance of homeothermy, elevation of blood volume, and nursing in mother rabbits. |
| |
Keywords: | Rabbit Vasopressin Oxytocin Immunochemistry Hypothalamus Pregnancy Parturition Estrus Maternal behavior |
本文献已被 ScienceDirect 等数据库收录! |
|