IDENTIFICATION OF CATECHOLAMINERGIC INPUTS TO AND OUTPUTS FROM AROMATASE-CONTAINING BRAIN-AREAS OF THE JAPANESE-QUAIL BY TRACT TRACING COMBINED WITH TYROSINE-HYDROXYLASE IMMUNOCYTOCHEMISTRY

In the quail brain, aromatase-immunoreactive (ARO-ir) neurons located in the medial preoptic nucleus (POM) and caudal paleostriatum ventrale /nucleus accumbens/nucleus striae terminalis complex (PVT/nAc/nST) rec eive catecholaminergic inputs identified by the presence of tyrosine h ydroxylase-immunoreactive (TH-ir) fibers and punctate structures. The origin of these inputs was analyzed by retrograde tracing with cholera toxin B subunit (CTB) or red latex fluospheres (RLF) combined with TH immunocytochemistry. CTB and RLF injected in the POM or PVT/nAc/nST w ere found in cells located in anatomically discrete areas in the telen cephalon (hippocampus, septum, archistriatum), hypothalamus (many area s in periventricular position), thalamus, mesencephalon, and pens. In these last two regions, many retrogradely labeled cells were located i n dopaminergic areas such as the retroruberal field (RRF), substantia nigra (SN), and area ventralis of Tsai (AVT) but also in noradrenergic cell groups such as the locus ceruleus and subceruleus. CTB tracing s howed that most of these connections are bidirectional. Many retrograd ely labeled cells contained TH-ir material. As a mean, 10-20% and 40-6 0% of the RLF-containing cells in the dopaminergic areas were TH-ir wh en RLF had been injected in the POM or PVT/nAc/nST, respectively. TH-i r cells projecting to the POM appeared to be mostly located in the per iventricular hypothalamus and in AVT, whereas projections to the PVT/n Ac/nST originated mainly in the SN (with significant contributions fro m the RRF and AVT). These data support the existence of functional rel ationships between aromatase and catecholamines. J. Comp. Neurol. 382: 401-428, 1997. (C) 1997 Wiley-Liss, Inc.