An MRI template of the female C57Bl/6N mouse brain

BACKGROUND: Brain templates are pivotal tools for standardized image analysis and interpretation in neuroimaging studies. However, matching data and reference remains essential. With growing awareness of sex as a relevant biological variable and male-centric biases in past medical investigations, the continuous limited use and availability of female-specific brain templates, particularly in preclinical research are alarming. METHODS: structural MRI brain template for female C57Bl/6N mice, a population-average derived from 153 axial and coronal scans of 80 female mice. We further analyzed the template's characteristics regarding the achieved effective resolution and compared it to currently available standard brains. Validation was performed by spatially normalizing external data to established templates and the novel reference, contrasting the degree of deformation. RESULTS: We present a readily applicable and accessible set of files (structural images, tissue probability maps, anatomical annotations, and transformation matrices) as reference for female-centric neuroimaging research questions. The novel template brain exhibits high nominal and effective resolution, differs significantly in spatial and cohort characteristics from previous references and shows improved performance with external data of female mice. CONCLUSION: We propose that integrating sex-specific tools into preclinical neuroimaging studies is essential for reducing sex bias, enhancing data reproducibility and strengthening the translational validity of neuroscientific findings. Research further disentangling (sub-)strain- and sex-differences is warranted.