NEUROBIOLOGY OF AGEING // LECTURE 1 // INTRO
LECTURE // 13-4-2021
➢ The oldest animals
→ Immortal: jellyfish is 1550 years: Antarctic sponges
→ What about mammals? 211 years old: Bowhead whale (Groenlandse walvis)
➢ Long-living creatures (brains)
- 1. Artica islandica: Reaches almost 400 years
→ “Ming” was 400 years old: to determine the age researchers had to open the shell,
causing Ming’s death....
→ Neurons by itself can also live that long → They need a lot of energy, so it’s impressive
that they can do that for 400 years
- 2. Bowhead whale
→ They found spearheads in these whales and they were sure that they were older than 200
years old
→ These animals are over 200 years old and probably even a little bit older
- 3. Oldest human being? We can reach 120 years…
→ The three oldest people of the world are all passed away now
→ The oldest verified man ever is Jiroemon Kimura (1897–2013) of Japan, who lived to the
age of 116 years and 54 days.
→ In Jeanne her situation people didn’t trust her birthday
➢ Oldest women in the world cheated…?
→ The chance was really large that she took over the identity of her mother
➢ Italica Grondona
→ Italica Grondona, age 102: apparently survived the Spanish flu and Covid-19
→ Her nickname: the immortal one (March 2020)
, ➢ Individual variation (at all levels of organization)
→ If you look at the brain and you look at healthy and sick areas and neurodegenerative
areas neurons are either healthy, sick or death and can just lie next to each other → It’s a
mix
→ So you can have dead and healthy neurons lying together
→ This is a kind of dichotomy that you have a healthy aging and pathological aging in the
same brain region
→ At the level of neurons and synapses you can have within the network of 2 neurons some
of these synapses can die while others stay healthy
→ Question: Why does one element grow old in a healthy way, but the other one
In a pathological way? Even if they live in the same environment.
→ You get a lot of individual variation
→ Depending on the age if you have younger ages then you see little individual variation,
but then typically in ageing you get a lot of variation and that some individuals do very good
or very bad → Some of the older individuals don’t differ from really young individuals →
These are then the ones that apparently age very successfully
➢ Functional consequences of brain-ageing in the fields of:
a) Cognition, e.g. learning and memory
b) Motor skills
→ Cognition and motor skills are very much interconnected, at least for humans
→ If you want to perform cognitively very well you can’t do that without good motor skills
→ You see that connection already during the development of the brain
→ A relatively part of the cortex of humans is dedicated to some kinds of motor aspects
→ These areas often change jointly in ageing
→ If you see a decline in cognition you also see a decline in motor performance
Many studies in developmental psychology show that motor development and cognitive
development cannot be viewed separately. Conclusions that can be drawn from these
studies indicate that well-developed motor functions correlate positively with successfully
performing cognitive tasks.
A few examples of motor skills that help you learn to read and write successfully:
- The child must have a well-developed basic balance. Then it may sit still well;
- The child must be able to carry its head properly without having to support the
head while performing writing and reading tasks;
- The eyes must, among other things, be able to focus to be able to read the texts;
, - The development of the body must be so matured that the child can perform fine
motor skills, such as the tweezers grip (“pincetgreep”) when writing;
- The child will have to master, recognize and experience rhythm and cadence in
order to be able to read;
- The sense of movement must be developed in such a way that the child moves the
pencil or pen onto the paper with just the right pressure;
- Primary reflexes must be under control so that no unnecessary energy is lost when
compensating for unwanted movements.
→ They found that children that sometimes have to redo a year more often were not so
physically active than those that never had to redo a year → So this is one example that
there is another clear correlation between the amount of physical activity and that
especially in sports is related to motor skills and cognitive performance
Daily physical activities and high quality physical education, especially in the age category
of 5-10 years, ensures:
- Fitter children and less overweight
- Better motoric skills, more participation in sports
- Positve effects on executive functions, memory and behavior
- Better performance in maths and language skills
- Less children that did not pass (have to redo a year)
- Less children that need special education
- Less costs in health care
→ If these children have a lot of physical activity and education that they have less
overweight and better motor skills and do better on executive functions, memory and
languages
→ Also less costs in health care
→ Question: which brain would you prefer to have while performing a memory test and
tapping a finger simultaneously?
→ The left brain has much less activity than the right person
→ Example of a mild concussion:
a) (working) memory and motor planning are connected
b) after mild damage more brain activity is needed to reach
the same (cognitive) outcome
→ This seems to be a rule of thumb in aging
,→ For performing a movement not only brain areas primary involved in the
implementation of the movement, but also those involved in the goal / consequence of
the movement
→ Right in the left picture is a person B that has had a concussion
→ They both were able to perform the task, but person B had to work very hard → So the
brain had to work very hard to reach a certain level of cognitive performance
→ So to answer the question is better to have brain A given the fact that they both could
master the task, but person B is what you see in ageing and that is for the older brain to
cope with all the changes in daily life the only thing it can do is to work harder and you get a
lot of extra activity to compensate for a less well functioning brain → That is also what you
have after a concussion → It’s more difficult for the brain to cope with all the information
processing
→ Old individuals that are able to activate that the brain to this level B are the ones that age
successfully and the ones that can’t cope are the ones that give up and can’t do the task etc.
,NEUROBIOLOGY OF AGEING // LECTURE 1 // PART 2
// INTRODUCTION BRAIN AGEING: LEARNING AND
MEMORY (1) // 13-4-2021
➢ What is (brain) ageing?
→ General vision about aging: It is not possible to determine when someone belongs to
the elderly as aging goes so slowly, and these changes per individual differ greatly. The
boundary is often drawn based on biological age and not on the basis of physical fitness
and resilience.
→ This course hopes to make more clear that, despite the complexity of aging, reasonably
clear "brain boundaries" can be drawn
➢ Healthy ageing: To understand the underlying mechanisms and to reduce the
morbidity
→ Mortality = Death rate; displays the number of deaths per 1000 inhabitants
over a period of time, usually one year.
→ Morbidity = Disease rate; it indicates the ratio of the number of sufferers of a particular
disease to the entire community within a given time period. The degree of morbidity is a key
figure that indicates the degree of occurrence of a certain disease
→ Comorbidity = the presence of one or more additional conditions co-occurring with (that
is, concomitant or concurrent with) a primary condition.
→ For example: The burden of medical comorbidity in individuals with Alzheimer's disease is
greater than that observed in matched individuals without dementia. It can come with a
number of other chronic medical conditions have been described, including thyroid
disorders, sleep apnea, osteoporosis and glaucoma.
➢ The age structure in the Netherlands and the “Gray Wave”
→ The “gray wave”: In 2040 >25% of the population is 65 or older (now: ca. 15%)
→ Older people are expensive at terms of health care and this age category that has to
pay/raise the money for the elderly here that needs health care
→ You more and more have to help keeping the health assurance doable also for the elderly
➢ Proportion of population aged 80 years or older in 2050 (anticipated)
→ Especially in Europe, China and Canada
, ➢ Life expectancy of the Dutch population
→ You see a gradual increase in the expectancy at birth and you also see that the difference
between the males and the females is relatively large and in favor of that for the females
and that’s getting smaller, because more boys / males were smokers than females
→ This is what they predict
→ You see that it still increases and in 2060 if you are being born then and you’re a female
then it can be expected that you can get as old as 90 years on average
→ For the males it’s still a little bit shorter
➢ What is normal ageing and what is pathological ageing?
→ An often used image is that you start with a young and healthy brain and gradually it
becomes old and diseased and in the end it’s a disaster
→ This is especially when you see normal aging and pathological aging viewed as continuum
without a clear turning point / change
→ The aging process (for cognitive function X) does not run smoothly
→ In reality you can have a steady brain condition and nothing is changing much, but then
suddenly it drops and you can have a temporarily dip from which you can recover
→ So it’s not at all a gradual and smooth process, but it goes with ups and downs and with
relatively long periods of more or less a stable condition
→ One of the things that can cause these dips is that you have a massive increase in
neuroinflammation (certain life event that is damaging your brain and you can either recover
from that (entirely or partly), but then in the end the most likely chance is that overall your
brain health is reduced permanently)
➢ Individual variation in cognitive ageing
→ If you get older than if you look at cognition you want to keep it okay and everything still
works well (called target area)
→ The target area prevents the elderly from moving in to the lower direction in this graph
