We investigated the distributions and interrelations of neuronal @entity842 (NO) synthase- ( @entity5612 ), @entity398 - (OT), and @entity1831 - (AVP) immunoreactive (IR) neurons in the paraventricular nucleus (PVN), and the occurrence and distribution of @entity5612 spinally projecting neurons in the PVN of the female @entity35 . Using double labelling immunohistochemistry, we mapped the distribution of @entity5612 -, OT- and AVP-immunoreactive (IR) neuronal cell bodies in the different parts of the PVN. About 80% of @entity5612 -IR cell bodies were magnocellular. About 30% of the @entity5612 -IR cell bodies were OT-IR, colocalization being most frequent in the rostral parts. In comparison, only approximately 3% of all @entity5612 -IR cell bodies were AVP-IR, evenly distributed throughout the PVN. @entity8125 ( @entity8125 ), administered unilaterally into the spinal cord, disclosed that most spinally projecting cell bodies in the PVN were localized in caudal parts. Combined @entity8125 tracing and @entity5612 immunohistochemistry showed that approximately 30% of spinally projecting neurons in the PVN were @entity5612 -IR, and that approximately 40% of these were magnocellular. Ipsilateral @entity5612 spinal projections were about eight times more frequent than the contralateral @entity5612 projections. The study describes the detailed neuroanatomical organization of @entity5612 neurons coexpressing OT or AVP, and of @entity5612 spinally projecting neurons within defined parts of the PVN. In contrast to the paraventriculo-spinal system in general, we show that the @entity5612 paraventriculo-spinal pathway to a large extent originates in magnocellular cell bodies. The results suggest that NO is an important messenger in the paraventriculo-spinal pathway that may in part act in concert with OT.

@entity842 synthase in the hypothalamic paraventricular nucleus of the female @entity35 ; organization of spinal projections and coexistence with XXXX or vasopressin.

@entity398 :: ('MESH:D010121', 'Chemical') :: ['oxytocin'] @entity1831 :: ('CHEBI:34543', 'Chemical') :: ['8-arginine vasopressin'] @entity8125 :: ('MESH:C579935', 'Disease') :: ['True Blue', 'TB'] @entity842 :: ('MESH:D009569', 'Chemical') :: ['nitric oxide'] @entity35 :: ('10116', 'Species') :: ['rat'] @entity5612 :: ('24598(Tax:10116)', 'Gene') :: ['nNOS']
@entity398 :: (MESH:D010121,Chemical) :: ['oxytocin']
