Postnatal Guinea Pig Brain Development, as Revealed by Magnetic Resonance and Diffusion Kurtosis Imaging

Area of Science:

• Neuroscience
• Developmental Biology
• Biomedical Imaging

Background:

• Understanding age-related brain development is crucial for interpreting neurobehavioral changes.
• Dunkin Hartley guinea pigs offer a valuable model for studying mammalian brain maturation.

Purpose of the Study:

• To investigate age-dependent changes in brain structure using in vivo magnetic resonance imaging (MRI) in male Dunkin Hartley guinea pigs.
• To characterize microstructural complexity and regional variations during brain maturation.

Main Methods:

• Acquisition of anatomical T2-weighted images, diffusion kurtosis imaging (DKI), and T2 relaxometry in guinea pigs at juvenile, adolescent, and young adult stages.
• Analysis of whole-brain and regional diffusion metrics, including fractional anisotropy (FA) and kurtosis measures.
• Comparison of diffusion tensor imaging (DTI) and DKI metrics to assess age-related microstructural changes.

Main Results:

• Significant increases in fractional anisotropy (FA) and kurtosis measures were observed in the corpus callosum, amygdala, striatum, and thalamus from juvenile to young adult stages.
• Age-related DKI metrics changes were more pronounced than diffusion tensor metrics changes.
• Less pronounced age-related changes in FA and kurtosis were noted in the parietal cortex and dorsal hippocampus.

Conclusions:

• Maturation significantly impacts the microstructural complexity of the male guinea pig brain.
• Age-dependent anatomical differences identified may be key determinants of neurobehavioral variations.
• DKI is a sensitive tool for detecting age-related microstructural alterations in the developing brain.