The photosensitive phase acts as a sensitive window for seasonal multisensory neuroplasticity in male and female starlings

Traditionally, research unraveling seasonal neuroplasticity in songbirds
has focused on the male song control system and testosterone. We
longitudinally monitored the song and neuroplasticity in male and female
starlings during multiple photoperiods using Diffusion Tensor and
Fixel-Based techniques. These exploratory data-driven whole-brain methods
resulted in a population-based tractogram uncovering microstructural
sexual dimorphisms in the song control system and beyond. Male brains
showed microstructural hemispheric asymmetries, whereas females had higher
interhemispheric connectivity, which could not be attributed to brain size
differences. Only females with large brains sing but differ from males in
their song behavior by showing involvement of the hippocampus. Both sexes
experienced multisensory neuroplasticity in the song control, auditory and
visual system, and the cerebellum, mainly during the photosensitive
period. This period with low gonadal hormones might represent a ‘sensitive
window’ during which different sensory and motor systems in telencephalon
and cerebellum can be seasonally re-shaped in both sexes.