Joint Mechanical Engineering and Biomedical Engineering Seminar: Gang Xu, D.Sc.

Experimental and Computational Study of the Mechanics of Brain Development

Research Assistant Professor, Department of Biomedical Engineering, Washington University

Abstract

The human brain undergoes tremendous morphological changes during development. It starts with a straight neural tube and eventually folds into a highly characteristic convoluted form. Anomalies in this process are associated with various genetic perturbations and neurological disorders. The available evidence suggests that mechanical forces play a crucial role in brain development. The specific biomechanical mechanisms for brain development, however, remain poorly understood.

This work focuses on two particular periods of brain development. The first is the early embryonic period of enlargement and differentiation of the neural tube into the primary brain subdivisions. The second is the later period of cerebral cortical folding. Based on both experimental and computational (finite element) studies on developing animal brains, we show:

1. that the geometric and mechanical characteristics of the brain tube may be optimized to facilitate early brain expansion and differentiation in response to increasing cavity pressure, and
2. that differential growth of cerebral cortex, not axonal tension, may play a primary role in driving cortical folding.

This study shows that a combination of experimental and computational mechanics can be used to explore and evaluate hypotheses of morphogenesis, and illuminate the biomechanics of brain development.