| Budget Amount *help |
¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1991: ¥500,000 (Direct Cost: ¥500,000)
Fiscal Year 1990: ¥900,000 (Direct Cost: ¥900,000)
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| Research Abstract |
Birdsong is a stereotyped behavior, yet its development depends on sensory feedback and learning. Song develops gradually during a birds ontogeny. When all aspects of song, including its duration, frequency range, and the form of the component sounds, become fixed, the song is said to be "Crystallized". Although adult birds annually go through a phase akin to combination of subsong and plastic song ages, they faithfully reproduce the crystallized song every year for the rest of their life.
Song is a hormonally controlled behavior. The birds sang in response to testosterone. Recording to neurons within the song system during singing shows that two of the forebrain nuclei, HVc and RA, in that order, constitute the forebrain motor pathway in vocal system for song control. One of neuropeptides, vasotocin(AVT)is known to have powerful physiological effect with regards to memory and learning. We examined localization of AVT cells and fibers in the zebra finch and bengalese finch brain with immunohistochemical technique. Vabotocin immunoreactive(ir-VT)cells and fibers formed a classical hypothalamic neurohypophyseal system in males and females. Ir-VT fibers were found in HVc and RA regions of song control system of only male. In lateral septum and dorsal diencephalon, the VT immunoreactivity was higher in males than in females.
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