The ontogeny of the canary HVC revealed by the expression of androgen and oestrogen receptors.
The vocal control nucleus HVC (nucleus hyperstriatalis ventrale, pars caudale) of the canary (Serinus canaria) is a model in which to study the relationship between anatomical plasticity and vocal developmental learning. Much of the structural plasticity of the HVC is sensitive to the action of androgenic and oestrogenic gonadal hormones that affect the brain by binding to androgen receptors (AR) and oestrogen receptors (ER). Here we report developmental changes of AR and ER expression in the HVC using in situ hybridization with avian specific cRNA probes. AR and ER are first expressed in the HVC at post-hatching day 10 (P10) and P30, respectively and are, therefore, present in the HVC throughout the singing-learning period of the canary. Because AR occur only in the caudal neostriatum of the HVC we mapped the size of the HVC with this marker. The size and neurone number of the AR-defined HVC reaches adult values at P30 and differentiates, therefore, independently of the singing activity and probably independently of oestrogens. Continuing neurogenesis in the HVC requires neuronal death and replacement from P30 on.
Gahr
M
M
Max Planck-Institute for Behavioural Physiology, Seewiesen, Germany.
Metzdorf
R
R
Aschenbrenner
S
S
D000818:Animals; D017209:Apoptosis / Q000502:physiology; D001717:Birds / Q000502:physiology*; D003001:Cloning, Molecular; D005260:Female; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D008297:Male; D017072:Neostriatum / Q000166:cytology / Q000254:growth & development* / Q000378:metabolism; D011944:Receptors, Androgen / Q000096:biosynthesis*; D011960:Receptors, Estrogen / Q000096:biosynthesis*; D013739:Testosterone / Q000494:pharmacology; D014828:Vocalization, Animal / Q000502:physiology*
D011944:Receptors, Androgen; D011960:Receptors, Estrogen; D013739:Testosterone