The neural substrate for song behaviour in songbirds, the song control system, is the best documented brain circuit to study neuroplasticity. Not only the volume ...
Using diffusion tensor imaging (DTI) to assess the neuronal plasticity in the brain of a songbird G. De Groof1, M. Verhoye1,2, A. Leemans2, A. Van der Linden1 1 2
Bio-Imaging Lab, University of Antwerp Vision Lab, University of Antwerp.
The neural substrate for song behaviour in songbirds, the song control system, is the best documented brain circuit to study neuroplasticity. Not only the volume of the key song control nuclei (SCN) HVC, RA and X change in size, but also the density of the connections between them changes as a function of seasonal and hormonal influences. Diffusion Tensor Imaging (DTI) visualizes bundles of axons connecting brain regions and the method has been used for human brain imaging but also recently in-vivo studies on small mammals have emerged [e.g. 1]. In the current study repeated in vivo DTI and the resulting parameters (FA=Fractional Anisotroptry, MD=Mean Diffusion, λr=Radial diffusivity, λ║=Axial diffusivity) were used to quantify seasonal changes in the connections between different SCN in starling brains. Nine male starlings (Sturnus vulgaris) were measured repeatedly in spring and in summer. DTI was performed on a 7T-system (MRRS) using multislice DW-SE and diffusion sensitizing gradients along 7 directions. Sagittal slices with image resolution of 100*100*400µm³ were obtained covering one hemisphere of the brain. FA (0.16±0.03 vs 0.22±0.03, p-value:
