Evolving Brains

Terrence Sejnowski

HHMISalk Institute

University of California, San Diego

Evolving Brains

Terrence Sejnowski

HHMISalk Institute

University of California, San Diego

Levels of InvestigationLevels of Investigation

“Nothing can be understood in Biologyexcept in the light of evolution”

T. Dobzhansky, 1973

“Nothing can be understood in Biologyexcept in the light of evolution”

T. Dobzhansky, 1973

Francis CrickJames Watson

“Nothing can be understood in Biologyexcept in the light of DNA”“Nothing can be understood in Biologyexcept in the light of DNA”

Natural SelectionNatural Selection

DifferentiationDifferentiation

DNA MethylationDNA Methylation

Neurons Reactivate a DNA MethylationProcess from Pluripotent Stem Cells

Neurons Reactivate a DNA MethylationProcess from Pluripotent Stem Cells

R. Lister*, E.A, Mukamel* et al.. Science (2013)

Fraction oftotal mC

Highly methylatedin all cell types

Assumedunmethylated

Neurons Accumulate DNA Methylation (mCH) During Brain Development

Neurons Accumulate DNA Methylation (mCH) During Brain Development

*DeFelipe et al. (1997); Huttenlocher et al., (1997)

R. Lister*, E.A, Mukamel* et al.. Science (2013)

Precise Patterns of mCHPrecise Patterns of mCH

R. Lister*, E.A, Mukamel* et al.. Science (2013)

Gene Expression is Correlated with mCHGene Expression is Correlated with mCH

M. Margarita BehrensM. Margarita Behrens Eran MukamelEran Mukamel

Ryan ListerRyan ListerJoe EckerJoe Ecker

Evolution of Body SegmentsEvolution of Body Segments

Evolution of Ion ChannelsEvolution of Ion Channels

Evolution of PhotoreceptorsEvolution of Photoreceptors

Evolution of VisionEvolution of Vision

Evolution of SynapsesEvolution of Synapses

Brain InnovationBrain Innovation

Evolution of the CortexEvolution of the Cortex

Evolution of the CortexEvolution of the Cortex

Evolution of VisionEvolution of Vision

Evolution of VisionEvolution of Vision

Felleman and Van Essen,1991

Evolution of VisionEvolution of Vision

A Tale of Two VolesA Tale of Two Voles

Montaine

Prairie

Young, Nilsen, Waymire, MacGregor and Insel, 1999

Repetitive expansion

Montane

Prairie

KE Family Tree

Evolution of LanguageEvolution of Language

Cerebellum

Inferior Olive

Caudate Nucleus

Thalamus

Cortical Plate

Substantia Nigra

Inferior Olive

Sydney Brenner

What Makes Humans Human?What Makes Humans Human?

DenisovanNeanderthalPresurfer

What Makes Humans Human?• Language• Hypersociality• Joint attention • Learning• Writing

John Allman

John Allman

Human BrainHuman Brain

Zhang and Sejnowski, 2000

Single Cell MethylomesSingle Cell Methylomes

Deep LearningDeep Learning

Picture CaptioningPicture Captioning

Picture CaptioningPicture Captioning

Dopamine NeuronsDopamine NeuronsActor Critic ModelActor Critic Model

Environment

Dopamine

Reward Prediction Error

Cerebral Cortex

BasalGanglia

Montague, Dayan and Sejnowski, 1996

I should have shown a better result, a better outcome, and better content in terms of the game played, and I do apologize for not being able to satisfy a lot of people’s expectations. I kind of felt powerless.

March 11, 2016: “AlphaGo can't beat me”

Ke Jie of ChinaKe Jie of China

January 5, 2017: “After humanity spent thousands of years improving our tactics, computers tell us that humans are completely wrong.”

Ke Jie of ChinaKe Jie of China

BRAIN InitiativeBrain Research through Advancing

Innovative Neurotechnologies

April 2, 2013

BRAIN InitiativeBrain Research through Advancing

Innovative Neurotechnologies

April 2, 2013 April 2, 2013

Advisory Committee to the NIH Director 

BRAIN 2025Brain Research through Advancing Innovative Neurotechnologies (BRAIN) Working Group

JUNE 05, 2014

Brain Activity Map

BRAIN InitiativeBRAIN Initiative