Organization of vasotocin‐immunoreactive cells and fibers in the canary brain

Abstract

The distribution of vasotocin (VT)-immunoreactive neuronal perikarya and fibers in the canary (Serinus canaria) was investigated with immunohistological techniques. The results suggest that most VT-stained cell bodies are located in three diencephalic regions. First, a large number of densely packed neurons are found in the paraventricular nucleus (PVN) and the anterior preoptic nucleus. Neurons here vary widely in size and shape. Small-size rounded neurons and large-size multipolar neurons appear to concentrate in separate subdivisions. Second, a series of loosely organized cell groups of medium- to large-size cells occurs in the lateral parts of the hypothalamus. These aggregates of neurons apparently correspond to subdivisions of the supraoptic nucleus (SON). Third, diffusely distributed, lightly stained cells are found dorsal to the paraventricular nucleus in the dorsal diencephalon. A number of cells of this group seem to be located in the basal septal area and bed nucleus of the stria terminalis. Immunoreactive fibers and varicosities concentrate in brain regions that are associated with neuroendocrine, autonomic, and limbic functions. Axons from the PVN and SON form compact bundles of the hypothalamohypophysial tract in the lateral hypothalamus and then funnel into the internal zone of the medium eminence (ME). Furthermore, a heavy innervation seems to be present in the palisadal, external zone of the ME. A substantial number of fibers appear to leave the PVN toward extrahypothalamic areas. Most extrahypothalamic VT fibers innervate telencephalic and brainstem regions that are thought to be involved in mediation of limbic and autonomic functions. These areas include the lateral and medial septum, the lateral habenula, the substantia grisea centralis, the area ventralis (Tsai), the locus coeruleus, raphe nuclei, the nucleus tractus solitarii, and lateral medulla. In addition, fibers with immunoreactivity for VT innervate structures such as the optic tectum and the nucleus ovoidalis that have been implicated in sensory processing of visual and auditory information. Finally, VT fibers and varicosities occur in centers including the nucleus robustus archistriatalis and nucleus intercollicularis that have been implicated in vocal control.

Testosterone Stimulates Mounting Behavior and Arginine Vasotocin Expression in the Brain of both Sexual and Unisexual Whiptail Lizards

“…Number of brains with total number of sections containing AVT-ir cells are indicated in the last column. 1992; birds: Kiss et al, 1987;Viglietti-Panzica et al, 1994;Jurkevich et al, 1996Jurkevich et al, , 1997Jurkevich et al, , 1999Jurkevich et al, , 2001Panzica et al, 1998Panzica et al, , 2001Kimura et al, 1999;Grossmann et al, 2002). A similar distribution of AVT-ir cell bodies and fibers was found in the brain of both whiptail lizard species.…”

Male Japanese quails with female brains do not show male sexual behaviors

“…One series of sections was immunostained for aromatase, one for gonadotropin-releasing hormone I (GnRH-I), and one for vasotocin under free-floating conditions, and then all were mounted on Superfrost slides. Immunostaining of aromatase, vasotocin, and GnRH-I followed published protocols employing the same antibodies (23)(24)(25). Control staining (using hypothalamic sections of other age-matched quails) omitting the primary antibody resulted in no cell labeling.…”

The parvocellular vasotocin system of Japanese quail: a developmental and adult model for the study of influences of gonadal hormones on sexually differentiated and behaviorally relevant neural circuits.

“…One group is located in the mesencephalon around the nucleus rotundus (3,4), and another group containing a larger number of neurons is present within the medial part of the avian nucleus of the stria terminalis (BSTm) (Figure 1). This latter group was first identified in oscine birds (5)(6)(7)(8) and later in galliforms (4,(9)(10)(11).…”

“…Their distribution has been studied in detail by immunocytochemistry in the brain of several avian species such as the canary (Serinus canaria) (5,13), the zebra finch (Taeniopygia guttata) (7), the Junco (Junco hyemalis) (8), and the Japanese quail (Coturnix japonica) (14)]. VT-ir fiber endings were observed in the telencephalon (lateral septum, BSTm), in the preoptic region [nucleus preopticus medialis (POM)], in broad areas of the diencephalon, in the mesencephalon [optic tectum, nucleus intercollicularis (ICo), substantia grisea centralis (GCt), area ventralis of Tsai, and substantia nigra], in the pons [raphe nuclei, locus coeruleus (LoC), and tegmentum], and in the medulla (nucleus of the solitary tract).…”