Dynamic Brain — The human brain across space and time

Abstract

Most anatomical illustrations show one brain, at one moment, from one angle. Dynamic Brain shows the organ as it really is: a three-dimensional structure that changes over a lifetime. Every surface is computed from population atlases of magnetic resonance images, every number is traced to a peer-reviewed source, and every schematic form is labelled as such.

0Atlas structures

0Developmental stages

0Fibre tracts

0Sourced data points

Development

From a smooth fetal brain
to the folded cortex.

Select a stage. Each shape is a population average from fetal, neonatal and paediatric MRI atlases, not an artist's impression.

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Fig. 2Fetal brain at 21 weeks of gestation. Shapes shown at equal size to compare folding.

Evolution

Half a billion years,
one organ.

Seven real brains, reconstructed from MRI and micro-CT. Each species is a living relative, not an ancestor: it shows what a lineage looks like after the same span of evolution as our own.

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Fig. 3

The neuron doctrine

Eighty-six billion cells,
each one an individual.

In 1888 Santiago Ramón y Cajal showed that the nervous system is made of discrete cells, not a continuous net. His drawings of stained neurons still define how we picture the brain.

Fig. 4Cortical pyramidal neurons in the manner of a Golgi preparation, drawn procedurally. Brass points are action potentials travelling from the dendrites to the axon.

≈ 86 bn

neurons in the adult human brain, about 16 billion of them in the cerebral cortex.

Azevedo et al., 2009

≈ 120 m/s

top conduction velocity of large myelinated axons, roughly 430 km per hour.

Classical electrophysiology

≈ 20 %

of the body's resting energy is used by an organ that makes up about 2 % of body weight.

Raichle & Gusnard, 2002

History of neurology

Thirty-six centuries
of looking inside.

From the first written word for "brain" to maps of every major fibre tract: the milestones this atlas stands on.

Methods

No invented shapes.

Built only from openly licensed data, checked twice against the original publications.

Data

Population atlases

MNI ICBM 152, CerebrA and CIT168 for the adult brain; CRL-2025, dHCP and NIHPD for development; seven species atlases for evolution; HCP1065 for fibre tracts.

Geometry

Computed surfaces

Surfaces are extracted from the segmentations with Surface Nets and Taubin smoothing. Nothing is modelled by hand.

Review

Second reading

An independent second review against the original papers confirmed 98.1 % of all data points. The rest were corrected.

The brain,
across space and time.

From a smooth fetal brain
to the folded cortex.

Half a billion years,
one organ.

Eighty-six billion cells,
each one an individual.

Thirty-six centuries
of looking inside.

No invented shapes.

Population atlases

Computed surfaces

Second reading

Open the atlas.

From a smooth fetal brainto the folded cortex.

Half a billion years,one organ.

Eighty-six billion cells,each one an individual.

Thirty-six centuriesof looking inside.

No invented shapes.

Population atlases

Computed surfaces

Second reading

Open the atlas.

From a smooth fetal brain
to the folded cortex.

Half a billion years,
one organ.

Eighty-six billion cells,
each one an individual.

Thirty-six centuries
of looking inside.