Asymmetry is present in the thalamofugal visual projections of female chicks.

Asymmetry of the thalamofugal visual projections of the chick has been previously reported to exist in males but not females. Using a larger sample size and a double-labelling procedure, projections to the visual Wulst were labelled with the retrograde tracers True Blue and Fluoro-gold and the ratio of contralateral projections to ipsilateral projections was calculated. We found that asymmetry does exist in female chicks, but to a lesser degree than in males.