Article

Structural changes between seasons in the songbird auditory forebrain.

Bio-Imaging Laboratory, University of Antwerp, Antwerp, Belgium.
Journal of Neuroscience (impact factor: 7.11). 10/2009; 29(43):13557-65. DOI:10.1523/JNEUROSCI.1788-09.2009 pp.13557-65
Source: PubMed

ABSTRACT The song control system (SCS) of seasonal songbirds shows remarkable seasonal plasticity. Male starlings (Sturnus vulgaris) sing throughout the year, but in the breeding season, when concentrations of testosterone are elevated, the song is highly sexually motivated. The main goal of this study was to investigate structural seasonal changes in regions involved in auditory processing and in socio-sexual behavior. Using in vivo Diffusion Tensor Imaging (DTI), we measured in breeding and nonbreeding seasons volume and tissue characteristics of several brain regions of nine adult male starlings. We demonstrate that the songbird brain exhibits an extreme seasonal plasticity not merely limited to the SCS. Volumetric analysis showed seasonal telencephalon volume changes and more importantly also a volumetric change in the caudal region of the nidopallium (NCM), a region analogous to the mammalian secondary auditory cortex. Analysis of the DTI data allowed detection of seasonal changes in cellular attributes in NCM and regions involved in social behavior. This study extends our view on a seasonally dynamic avian brain which not only hones its song control system but also auditory and social systems to be prepared for the breeding season.

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Keywords

adult male starlings
 
brain regions
 
caudal region
 
DTI data
 
main goal
 
Male starlings
 
nonbreeding seasons volume
 
region analogous
 
regions
 
seasonal songbirds
 
seasonally dynamic avian brain
 
social behavior
 
social systems
 
socio-sexual behavior
 
song control system
 
songbird brain exhibits
 
Sturnus vulgaris
 
tissue characteristics
 
vivo Diffusion Tensor Imaging
 
Volumetric analysis