Abstract
Immunofluorescent labeling of synaptic vesicle protein 2 (SV2) and confocal microscopy were employed to assess the role of synapse density in the functioning of the avian song system. Synapse density in premotor nuclei HVC and RA was measured, in both sexes of two species characterized by male-only singing behavior: the zebra finch Taeniopygia guttata, which sings a single, stereotyped song, and the Carolina wren Thryothorus ludovicianus, which sings a large repertoire of different songs. Multiple levels of analyses demonstrate overall similarity of synapse density between nuclei HVC and RA, suggesting that synapse density is regulated uniformly across these regions within individuals. Male zebra finches and male Carolina wrens have equivalent synapse densities, suggesting a common pattern of masculinized development despite dramatic behavioral differences. Female Carolina wrens have synaptic density similar to that of males of both species, while female zebra finches exhibit greater synaptic densities in both regions than do male zebra finches or both sexes of wrens. Prior reports implicate testosterone as a regulator of synapse density in this system; sex differences in circulating or neural testosterone may contribute to the sexual dimorphism of synapse density observed here. Interspecific comparison of song system synapse density in nonsinging females suggests that synapse density in female songbirds may be a particularly labile trait.
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Disclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.