The medial preoptic nucleus receives vasotocinergic inputs in male quail: a tract-tracing and immunocytochemical study.
The sexually dimorphic testosterone-sensitive medial preoptic nucleus (POM) of quail can be identified by the presence of a dense network of vasotocinergic fibers. This innervation is sexually differentiated (present in males only) and testosterone sensitive. The origin of these fibers has never been formally identified although their steroid sensitivity suggests that they originate in parvocellular vasotocinergic neurons that are found in quail only in the medial part of the bed nucleus striae terminalis (BSTm) and in smaller numbers within the POM itself. We report here that following injections of a retrograde tracer into the POM of male quail, large populations of retrogradely labeled cells can be identified in the BSTm. The POM also receives afferent projections from magnocellular vasotocinergic nuclei, the supraoptic and paraventricular nuclei. Double labeling for vasotocin immunoreactivity of the retrogradely labeled sections failed however to clearly identify magnocellular vasotocin-immunoreactive cells that were retrogradely labeled from POM. In contrast a substantial population of vasotocin-immunoreactive neurons in the BSTm contained tracer retrogradely transported from the POM. These data therefore demonstrate that a significant part of the vasotocinergic innervation of the quail POM originates in the medial part of the BST. An intrinsic innervation could however also contribute to this network. This interaction between BSTm and POM could play a key role in the control of male-typical sexual behavior and in its sex dimorphism in quail.
Absil
Philippe
P
Center for Cellular and Molecular Neurobiology, Research Group in Behavioral Neuroendocrinology, University of Liège, 17 Place Delcour, B-4020 Liege, Belgium.
Papello
Monica
M
Viglietti-Panzica
Carla
C
Balthazart
Jacques
J
Panzica
GianCarlo
G
D000818:Animals; D001370:Axonal Transport / Q000502:physiology; D003370:Coturnix / Q000033:anatomy & histology / Q000502:physiology*; D005456:Fluorescent Dyes / Q000032:analysis; D007150:Immunohistochemistry; D008297:Male; D009412:Nerve Fibers / Q000737:chemistry* / Q000502:physiology; D011301:Preoptic Area / Q000033:anatomy & histology / Q000737:chemistry* / Q000378:metabolism; D012733:Sex Differentiation / Q000502:physiology; D013194:Staining and Labeling; D014668:Vasotocin / Q000032:analysis* / Q000096:biosynthesis
D005456:Fluorescent Dyes; D014668:Vasotocin