living matter lab


fall 14 - me334 - mechanics of the brain


me 334 - mechanics of the brain 14

ellen kuhl
office hours tue 2:00-3:00, durand 217
it's all about the brain
announcement, syllabus

fall 2014
tue thu 11:00-12:15

dissecting brains


our brain is not only our softest, but also our least well-understood organ. floating in the cerebrospinal fluid, embedded in the skull, it is almost perfectly isolated from its mechanical environment. not surprisingly, most brain research focuses on the electrical rather than the mechanical characteristics of brain tissue. recent studies suggest though, that the mechanical environment plays an important role in modulating brain function. neuromechanics has traditionally focused on the extremely fast time scales associated with dynamic phenomena on the order of milliseconds. the prototype example is traumatic brain injury where extreme loading rates cause intracranial damage associated with a temporary or permanent loss of function. neurodevelopment, on the contrary, falls into the slow time scales associated with quasi-static phenomena on the order of months. a typical example is cortical folding, where compressive forces between gray and white matter induce surface buckling. to understand the role of mechanics in neuroanatomy and neuromorphology, we begin this course by dissecting mammalian brains and correlate our observations to neurophysiology. we discuss morphological abnormalities including lissencephaly and polymicrogyria and illustrate their morphological similarities with neurological disorders including schizophrenia and autism. then, we address the role of mechanics during brachycephaly, plagiocephaly, tumor growth, and hydrocephalus. last, we explore the mechanics of traumatic brain injury with special applications to shaken baby syndrome.


  • 20 % dissection - presentation and written report, 10% each
  • 30 % homework - three homework assignments, 10% each
  • 20 % project presentation - graded by the class
  • 30 % project report - graded by instructor


day date topic slides homework
tue sep 23 introduction to brain anatomy s01
thu sep 25 introduction to brain mechanics s02
tue sep 30 dissecting brains s03
thu oct 02 brain anatomy - student presentations s04
tue oct 07 brain mechanics in 1d – elasticity of neurons s05
thu oct 09 brain growth in 1d – growth of axons s06
tue oct 14 brain growth in 2d – morphogenesis s07
thu oct 16 brain growth in 3d – evolution and development s08
tue oct 21 brain growth in 3d – physiology and pathology s09
thu oct 23 brain mechanics in 3d – elasticity of the brain s10
tue oct 28 brain mechanics in 3d – viscoelasticity and multiple sclerosis s11
thu oct 30 brain mechanics in 3d – viscoelasticity and aging s12
tue nov 04 brain tumor growth in 3d – brain tumors s13
thu nov 06 brain tumor growth in 3d – brain tumors s14
tue nov 11 brain surgery - craniosynostosis and intracranial pressure s15
thu nov 13 brain surgery - brain tumors and craniosynostosis s16
tue nov 18 brain dynamics in 1d - diffuse axonal injury s17
thu nov 20 brain dynamics in 3d – traumatic brain injury, shaken baby syndrome s18
tue dec 02 final projects - discussion, presentation, evaluation s19
thu dec 04 final projects - discussion, presentation, evaluation s20
fri dec 05 final project reports due

matlab files

here's the matlab code for brain folding

additional reading

bayly pv, taber la, kroenke cd. mechanical forces in cerebral cortical folding: a review of measurements and models. j mech beh biomed mat. 2014;29:568-581. (download)

budday s, steinmann p, kuhl e. the role of mechanics during brain development. j mech phys solids. 2014:72:75-92. (download)

budday s, raybaud c, kuhl e. a mechanical model predicts morphological abnormalities in the developing human brain. scientific reports. 2014;4:5644. (download)

budday s, nay r, steinmann p, wyrobek t, ovaert tc, kuhl e. mechanical properties of gray and white matter brain tissue by indentation. submitted for publication. 2014. (download)

dennerll tj, lamoureux p, buxbaum re, heidemann sr. the cytomechanics of axonal elongation and retraction. j cell bio. 1989;109:3073-3083. (download)

franceschini g, bigoni d, regitnig p, holzapfel ga. brain tissue deforms similar to filled elastomers and follows consolidation theory. j mech phys solids. 2006;54:2592-2620. (download)

hardan ay, libove ra, keshavan ms, melhem nm, minshew nj. a preliminary longitudinal magnetic resonance imaging study of brain volume and cortical thickness in autism. biol psych. 2009;66:320-326. (download)

kruse sa, rose gh, glaser kj, manduca a, felmlee jp, jack cr, ehman rl. magentic resonance elastography of the brain. neuroimage. 2008;39:231-237. (download)

miller k, chinzei k. constitutive modelling of brain tissue: experiment and theory. j biomech. 1997;30:1115-1121. (download)

raybaud c, widjaja e. development and dysgenesis of the cerebral cortex: malformations of cortical development. neuroimag clin n am. 2011;21:483–543. (download)

richman dp, stewart rm, hutchinson jw, caviness vs. mechanical model of brain convolutional development. science. 1975;189:18-21. (download)

sun t, hevner rf. growth and folding of the mammalian cerebral cortex: from molecules to malformations. nature neurosci. 2014;15:217-231. (download)

van essen dc. a tension-based theory of morphogenesis and compact wiring in the central nervous system. nature. 1997;385:313-318. (download)