Nature, nurture & neuroplasticity | Anthony Hannan | TEDxNorthernSydneyInstitute

Summary

This talk delves into the enigmatic 'light bulb moment' in neuroscience, highlighting three transformative revolutions: neuroplasticity, which shows the brain's adaptability throughout life; genomics, promising personalized medicine through DNA sequencing; and epigenetics, revealing how environmental factors can alter gene expression. It emphasizes the brain's development, the impact of disorders, and the potential for new treatments, concluding with the hopeful message that our genetic destiny can be influenced by our experiences.

Takeaways

• 🧠 The 'light bulb moment' is a mystery in neuroscience and remains one of the exciting areas to explore.
• 🌟 Einstein's quotes highlight the importance of embracing the mysterious and the awe it inspires, which is also true for understanding the brain.
• 🧬 The brain is a complex 'mind machine' with 100 billion neurons and a thousand trillion synapses, unlike any supercomputer.
• 🔄 Neuroplasticity is a revolutionary concept showing the brain's ability to change and adapt throughout life, not just in childhood.
• 📈 Experience and environment can alter brain connections, even leading to the birth of new neurons in adulthood.
• 🧪 Brain scans reveal how the brain develops and changes from childhood to adulthood, influenced by experiences.
• 🌐 Brain and mind disorders affect a significant portion of the population, emphasizing the importance of understanding and treating them.
• 🧬 Genomics is revolutionizing healthcare with the potential for personalized medicine through DNA sequencing.
• 🌿 Environmental factors play a crucial role in brain disorders, and understanding them is key to developing treatments.
• 🧬 Epigenetics refers to changes above the genome, influencing how genes express themselves without altering the DNA sequence.
• 🏋️‍♂️ Cognitive stimulation and physical activity can have therapeutic effects, potentially delaying the onset of brain disorders.

Q & A

What is the 'light bulb moment' in neuroscience?

The 'light bulb moment' is a metaphor for a sudden realization or a moment of insight. The neuroscience behind it remains a mystery, making it an exciting area of study.

What are the three revolutions mentioned in the script that will transform lives in the 21st century?

The three revolutions are neuroplasticity, genomics, and epigenetics. These revolutions have the potential to transform our understanding of the brain and mind, leading to advancements in healthcare and treatment of brain disorders.

How does neuroplasticity challenge the previous understanding of the adult brain?

Neuroplasticity challenges the previous understanding that the adult brain is fixed by showing that the brain can change its structure and function throughout life, not just in childhood.

What is the significance of the brain's ability to change its connections and even create new neurons in adulthood?

The ability to change connections and create new neurons in adulthood is significant because it demonstrates the brain's adaptability and capacity for growth, which can have implications for learning, memory, and recovery from brain injuries.

How does the brain's development continue throughout life?

The brain's development continues throughout life as it forms new connections and modifies existing ones in response to experiences and the environment.

What is the impact of brain and mind disorders on the population?

Brain and mind disorders affect a significant portion of the population, with 75% of individuals expected to suffer from at least one such disorder in their lifetime.

How does genomics revolutionize healthcare?

Genomics revolutionizes healthcare by enabling the sequencing of an individual's entire genome at a low cost. This can lead to personalized and precision medicine tailored to an individual's genetic makeup.

What is the role of environmental factors in brain disorders?

Environmental factors play a significant role in brain disorders, often interacting with genetic predispositions to influence the development and progression of these conditions.

What was the outcome of the experiment involving mice with Huntington's disease and environmental enrichment?

The experiment showed that mice with Huntington's disease that received increased cognitive stimulation and physical activity experienced a dramatic delay in the onset and progression of the disease.

How does epigenetics differ from genetics?

Epigenetics refers to chemical modifications to DNA that can affect gene expression without changing the DNA sequence itself, whereas genetics involves the study of genes and their variations.

What is the concept of 'brain reserve' and how can it be beneficial?

The concept of 'brain reserve' suggests that increased cognitive stimulation and physical activity can build a neuroprotective reserve within the brain, potentially delaying the onset of neurodegenerative diseases.

Outlines

00:00

💡 The Mystery of the Light Bulb Moment

The speaker begins by acknowledging the elusive nature of understanding the 'light bulb moment' from a neurobiological perspective. They emphasize the excitement of working in an area where answers are not yet known. The speaker then introduces three revolutions that will impact lives in the 21st century. They quote Albert Einstein, highlighting the beauty of the mysterious as a source of art and science. The brain is described as a 'mind machine' with 100 billion neurons and a thousand trillion synapses, contrasting it with supercomputers that lack 'light bulb moments.' The first revolution discussed is neuroplasticity, which challenges the old belief that the adult brain is fixed. The speaker explains how experiences and the environment can change the brain's structure and function, even leading to the creation of new neurons in adulthood.

05:00

🧬 The Genomics Revolution and Brain Disorders

The second paragraph focuses on the genomics revolution, where the cost of sequencing a person's genome is dropping rapidly, leading to personalized and precision medicine. The speaker discusses the prevalence of brain and mind disorders, affecting 75% of the population at some point in their lives. They emphasize the importance of understanding and treating these disorders. The speaker then delves into the relationship between genetics and environmental factors in causing brain disorders. They share a personal experience with Alzheimer's disease and present statistics on the global impact of brain disorders. The speaker also discusses the need for a comprehensive approach to understanding these disorders, combining genetic data with environmental data.

10:01

🌿 The Impact of Environment on Brain Health

In the third paragraph, the speaker shares a 'light bulb moment' from their research on a mouse model of Huntington's disease. They found that environmental enrichment, including increased cognitive stimulation and physical activity, could delay the onset and progression of the disease. The speaker suggests that neuroplasticity at the cellular level may be responsible for this effect. They introduce the concept of the 'epigenetic landscape,' explaining how genetic and environmental factors influence brain development and the potential for disorders such as autism and schizophrenia. The speaker concludes by discussing the concept of 'brain reserve,' which can be built through cognitive stimulation and physical activity, potentially protecting against diseases like Alzheimer's. They propose the idea of 'enviromemetics' as a new therapeutic approach that could mimic the beneficial effects of cognitive stimulation and exercise.

Keywords

💡Neuroscience

Neuroscience is the scientific study of the nervous system, which includes the brain, its structure, function, and impact on behavior. In the video, neuroscience is central to understanding the 'light bulb moment,' which is a metaphor for a sudden realization or idea. The speaker highlights the mystery surrounding this phenomenon, indicating that neuroscience is still uncovering the brain's complexities.

💡Neuroplasticity

Neuroplasticity, also known as brain plasticity or neural plasticity, refers to the brain's ability to change and adapt as a result of experience. The video emphasizes that until recently, it was believed that the adult brain was fixed, but the revolution of neuroplasticity has shown that the brain can rewire and even generate new neurons throughout life, which has profound implications for learning, memory, and recovery from brain injury.

💡Genomics

Genomics is the study of all the genes in an organism, including their functions and interactions. In the context of the video, genomics is highlighted as a revolution that will transform medicine by enabling the sequencing of an individual's entire genome. This could lead to personalized and precision medicine, tailoring treatments to an individual's genetic makeup.

💡Epigenetics

Epigenetics is the study of changes in gene expression that do not involve alterations to the genetic code but still get passed down to at least one successive generation. The video explains that epigenetics involves chemical modifications to DNA that can be influenced by the environment and can affect gene expression without changing the DNA sequence itself.

💡Brain Disorders

Brain disorders are conditions that affect the structure or function of the brain and can lead to cognitive, emotional, or behavioral impairments. The video discusses a range of brain disorders, emphasizing the personal impact these conditions have on individuals and their families, and the importance of research in understanding and treating them.

💡Cognitive Stimulation

Cognitive stimulation refers to activities or experiences that challenge the brain to think, learn, and remember. In the video, it is suggested that cognitive stimulation can have a positive impact on brain health, potentially delaying the onset of brain disorders and enhancing neuroplasticity.

💡Physical Activity

Physical activity is any bodily movement that works your muscles and requires energy. The video script mentions that, along with cognitive stimulation, physical activity can contribute to brain health and may be therapeutic for certain brain diseases by promoting neuroplasticity.

💡Huntington's Disease

Huntington's disease is a hereditary brain disorder that leads to the breakdown of nerve cells in certain areas of the brain. It is mentioned in the video as an example of a condition that was once thought to be entirely genetically determined, but environmental factors, such as cognitive stimulation and physical activity, can influence its progression.

💡Synapses

Synapses are the junctions through which neurons transmit signals to one another. The video explains that the brain's complexity and its ability for neuroplasticity are due to the vast number of synapses that neurons can form, allowing for the processing of large amounts of information.

💡Brain Reserve

Brain reserve is the concept that a brain with a higher cognitive reserve is better equipped to withstand the effects of damage or disease. The video suggests that cognitive stimulation and physical activity can build a neuroprotective reserve that may protect against brain disorders like Alzheimer's disease.

💡Enviromemetics

Enviromemetics is a term coined in the video to describe potential new therapeutics that mimic or enhance the beneficial effects of cognitive stimulation and physical exercise. The idea is to develop treatments that can provide the brain with similar protective benefits as those gained from environmental enrichment.

Highlights

Understanding the 'light bulb moment' is one of the mysteries of neuroscience.

Three revolutions will transform lives in the 21st century.

Albert Einstein's quote on the mysterious being a source of all true art and science.

The brain is a mind machine with 100 billion neurons connected by a thousand trillion synapses.

The revolution of neuroplasticity shows the adult brain is not fixed and can change throughout life.

Neuroplasticity involves how experience and environment sculpt the brain.

The brain is the only organ that never stops developing.

MRI brain scans show the brain's development from age 5 to 20.

1.5 billion people worldwide are affected by brain and mind disorders.

The revolution of genomics allows sequencing of the entire human genome for a few hundred dollars.

Genomics and environmental data are needed to understand complex brain disorders.

A study on a mouse model of Huntington's disease showed environmental enrichment can delay disease progression.

Neuroplasticity at the cellular level allows for new connections and may be therapeutic for brain diseases.

The revolution of epigenetics refers to chemical modifications of DNA without changing its sequence.

Epigenetics and neuroplasticity suggest our genomes and brains may be maladapted to current environments.

The concept of brain reserve is relevant to disorders like Alzheimer's disease.

Cognitive stimulation and physical activity build a neuroprotective reserve within the brain.

Enviromemetics are potential new therapeutics that mimic the effects of cognitive stimulation and physical exercise.

Neuroplasticity and brain reserve can shift the pathway towards healthy brain maturation and function.

Transcripts

the light bulb moment

so if you're expecting me to come here

and tell you the neurobiology

of the light bulb moment

then you'll be disappointed and you can

leave now

understanding the light bulb moment is

one of the mysteries of neuroscience we

don't have the answers and it makes it

an extraordinarily exciting area to work

in

what i will tell you about

are three revolutions which will

transform your lives and the lives of

everyone in the 21st century

i have here three quotes from albert

einstein one of the greatest minds of

the 20th century

my favorite one

is the final quote

the most beautiful thing we can

experience

is the mysterious

it is a source of all true art and all

science

he to whom this emotion is a stranger

who can no longer pause to wonder and

stand wrapped in awe

is as good as dead

his eyes are closed

you can see from the first quote that

even for a genius

light bulb moments don't come easily

so the brain is a mind machine

i use this term

used in a book by that name by colin

blakemore

a couple of decades ago

there's 100 billion neurons connected by

a thousand trillion synapses the

connections between them

so the most powerful supercomputers in

the world

don't have light bulb moments

it's this kilogram and a half of soft

tissue in your skulls that facilitates

everything you feel

everything you think

and everything you do

so the first revolution i'll tell you

about

is the revolution of neuroplasticity

so until a couple of decades ago

we thought the adult brain was fixed

it was a machine it was like a computer

so this revolution involves

understanding

how your experience how the environment

sculpts your brain not just in childhood

but in adulthood it changes connections

between neurons

it can even cause the birth of new

neurons in your adult brain

and hopefully

if you do remember anything from this

talk

that will have left a structural and a

functional change in your brain

that allows you

to remember it and maybe helps you

generate your own

light bulb moment

here's a type of brain plasticity that

you can all understand

that of learning and memory

neurons that wire together

fire together

so it's the connections between them

that are important

so the brain is unique in another way

it's the only organ in the body that

never stops developing

you can see here images developed from

mri brain scans in healthy individuals

from the age of five

through to twenty

if you look at the bottom left what you

see there is a change in the brain in

childhood you have extra connections and

you have more gray matter in the

cerebral cortex and your experience

over this period in fact throughout your

life

sculpts your brain

which is what is shown there in the

changing that occurs in the thickness of

the gray matter during this period

on the bottom right

is the brain shown from the right side

so we're not just doing this for

curiosity

at the floor institute we're looking at

a range of brain and mind disorders and

so i've shown here just some of the

brain and mind disorders and other

neurological disorders

that we work on

so i want to show of hands

so could everyone in the audience who's

been personally affected who's had a

family member

or a friend affected by one or more of

these brain disorders could you raise

your hand

well that's extraordinary but expected

so my dear aunt died a few months ago

after suffering horribly from

alzheimer's disease

and she had a very bright mind so it was

absolutely shocking to see it completely

dimmed

by dementia

and so it's often that we only

understand the power of the human brain

when we see it

destroyed by brain disease

so here's some numbers for you

you can see

1.5 billion in rising people affected

worldwide by brain and mind disorders

and you see there that 75 of the

population will suffer from at least one

brain disorder

in their lifetime

so we hear almost every day

that our country is facing another

crisis so the question is what can be

more important

than learning how to prevent

to treat and eventually cure

these

and other diseases

of the brain and the body

so on to the second revolution

this is a revolution of genomics

so we're rapidly reaching a point where

the three billion base pairs of dna

in your genome in every cell in your

body

can be sequenced for less than a few

hundred dollars per person

this will mean that you will carry your

genome probably on a credit card sized

device

that you will hand it to your gp and

other healthcare professionals and

clinicians

and this will dictate the way in which

personalized and precision medicine is

delivered to you

providing our health care systems

can support that new technology

but it will change your lives

so back to brain and mind disorders

each one of them is caused by a

combination of genetic

and environmental factors

you can see some of these major brain

disorders listed here

so there's a lot of focus on genomics

the study

of the genome

of all individuals those who are healthy

those with particular diseases

however i would suggest that in parallel

what we need

is a field of environments where we

gather data on individuals which needs

to go from conception through to old age

quantitative data hard data on large

populations which is what's happening

with genomics at the moment and we need

to put those two together

that's the level of information we need

to understand the cause of these very

complex brain disorders and to use that

information to develop new treatments

all right here's a little slide here for

the geneticists in the audience i assume

there are none

so in order to understand a disease we

need a good model

and to do that we need to sort the sheep

from the goats

i'm going to tell you now about

a light bulb moment that i had

so we were studying

a mouse model of huntington's disease

and at the time in the 1990s it was

considered the epitome of genetic

determinism 100

genetic it's a fatal brain disease

inherited by half the children when one

of the parents has huntington's disease

so i wanted to challenge the dogma and

with a graduate student anton van delen

what we did was divide the mice up into

those that received standard housing

conditions were a little bit boring

and those conditions in which there was

increased cognitive stimulation

and increased physical activity

and what we found in this experiment was

quite striking

you can see here a measure

in this graph

of huntington's disease the symptoms

going up with standard housing to 100

percent

in this adult mouse model of

huntington's disease

what we found if you see

in the bottom of the graph with

environmental enrichment there was a

dramatic delay

in onset and progression of huntington's

disease due to this increased cognitive

stimulation

and physical activity

so how might this happen

one of the ways we think this might

happen

is at the level of neuroplasticity of

individual cells

so neurons are the most extraordinary

cells in the body

a single neuron can receive thousands of

connections or synapses from other

neurons

and it's this complexity that allows the

brain to process

enormous amounts of information

but it also allows for an enormous

amount

of neuroplasticity

so you can see an example here

whereby the environmental enrichment

leads to the creation of new connections

new synapses and this may be the way in

which it can actually be therapeutic

with respect to these kind of brain

diseases

so on to the third revolution

this is the revolution of epigenetics

so what this refers to you can see the

beautiful double helical strand of dna

that has

molecules attached to it so it refers to

chemical modification of dna essentially

it's above the genome without changing

the

letters of dna

so what you're seeing here

is

an epigenetic landscape this term comes

back to conrad waddington and the first

description of epigenetics

so imagine on this

epigenetic landscape

that the rolling stone

is brain development

and this is partly dictated by the

genetics which dictates the trajectory

of brain development along particular

pathways

the rest of this pathway is dictated by

the environment

and experience

and it can shift development in

different ways

now what we know

is that genomes evolve

over thousands of years

so essentially you have the genome

and the brain and the body that's very

similar to that of our hunter-gatherer

ancestors

so if any particular disease including

brain disorders is changing in incidence

or prevalence

the implication is not that the genome

is changing

it's that there are changes in

environment which perhaps our genomes

and our brains and our bodies

are maladapted to

this may have relevance to disorders of

brain development for example

autism and schizophrenia

another implication of this

epigenetics and neuroplasticity

is the concept of brain reserve

so brain reserve may be most relevant

to disorders such as alzheimer's disease

and other forms of dementia

what occurs here is that this increased

cognitive stimulation and physical

activity

builds a neuroprotective reserve within

the brain

now the concept is that if we can

understand how this cognitive

stimulation physical activity

is protective and beneficial at the

level of molecules and the level of

cells

then we could develop

enviromemetics

these would be new therapeutics which

mimic or enhance the beneficial effects

of this cognitive stimulation and

physical exercise

so finally

we're all dealt a genetic deck of cards

at conception that we can do nothing

about

many of us due to our genomes and our

genetic predisposition

start to move down the red pathway

towards a particular brain disorder

however

thanks to neuroplasticity and brain

reserve

this pathway can be shifted towards the

left

the green pathway which is the pathway

that we all want to be on

so this would be the pathway

where we have

healthy brain maturation

brain function

and aging

so that these light bulb moments can

continue throughout life

thank you

you