Navegando por Assunto "Aves canoras"

Agora exibindo 1 - 2 de 2

Acesso aberto (Open Access)
Identificação neuroanatômica dos núcleos cerebrais relacionados ao canto em Uraeginthus cyanocephalus (ordem Passeriformes, subordem Oscines, família Estrildidae)
(Universidade Federal do Pará, 2011-09-28) LOBATO, Muriele Nazareth; LIMA, Silene Maria Araújo de; http://lattes.cnpq.br/8961057812067156
Song control regions in passerine birds are sexually dimorphic in the adult brain of species like the zebra finches in which males sing whereas females do not. In the majority of tropical bird species, however, females sing as well. The issue of female song production began to attract more attention recently, but the neural mechanisms involved in the female song production are still poorly understood. Here we study for the first time the ontogeny of the song control system in a species, in which both male and female sing regularly. In blue-capped cordon blues (Uraeginthus cyanocephalus), a close relative of the zebra finch, females sing but have shorter songs with fewer syllables compared to the males. Volumetric changes of forebrain song control regions (the HVC, the RA and the LMAN) of the blue capped cordon bleu have been quantified in both sexes at 20, 30, 50 and ≥100 days posthatching, by using the Nissl- taining method and in situs hybridization. In both sexes, no significant differences in the volumetric development of HVC (proper name) were detected. The Nissl-efined volume of the HVC in males was always superior to the females values, including the adulthood, when the volume values became significant bigger in males than in females. In contrast, the volume of the robust nucleus of the archistriatum (RA) increased with age reaching the highest values in adulthood. The Nissl-defined RA volume incresed by 2,21 times in males (from 0,104 mm3 at 20 days to 0,236 mm3 in adulthood). In females, no significant differences in the volumetric development of RA were detected.
Acesso aberto (Open Access)
A putative RA-like region in the brain of the scale-backed antbird, Willisornis poecilinotus (Furnariides, Suboscines, Passeriformes, Thamnophilidae)
(Universidade Federal do Pará, 2015-09) LIMA, Jamily Lorena Ramos de; SOARES, Luiz Fabrício Angioletti; REMÉDIOS, Ana Cláudia Santana dos; SILVA, Gregory Thom e; WIRTHLIN, Morgan; ALEIXO, Alexandre Luis Padovan; SCHNEIDER, Maria Paula Cruz; MELLO, Claudio Vianna de; SCHNEIDER, Patrícia Neiva Coelho
The memorization and production of song in songbirds share important parallels with the process of speech acquisition in humans. In songbirds, these processes are dependent on a group of specialized telencephalic nuclei known as the song system: HVC (used as a proper name), RA (robust nucleus of arcopallium), LMAN (lateral magnocellular nucleus of the nidopallium) and striatal Area X. A recent study suggested that the arcopallium of the Sayornis phoebe, a non vocal learner suboscine species, contains a nucleus with some properties similar to those of songbird RA, suggesting that the song system may have been present in the last common ancestor of these groups. Here we report morphological and gene expression evidence that a region with some properties similar to RA is present in another suboscine, the Amazonian endemic Willisornis poecilinotus. Specifically, a discrete domain with a distinct Nissl staining pattern and that expresses the RA marker RGS4 was found in the arcopallium where the oscine RA is localized. Our findings, combined with the previous report on the S. phoebe, suggest that an arcopallial region with some RA-like properties was present in the ancestor of both Suboscines infraorders Tyranni and Furnarii, and is possibly an ancestral feature of Passeriformes.