Healthy Brain Lectures
HBL Part 1: Introduction
What is the core question that we want to answer regarding getting a healthy brain? What do
we need to ask in order to get an answer to this question?
- Can we influence brain health?
- What is the current state of neurobiological research into behavioral interventions to
increase brain health and mental well-being?
These lectures are focused on interventions for increasing brain health in healthy people.
The main focus is on psychological well-being and a small part is on peak performance
(such as studying and exams).
Where does ‘psychological well-being’ or ‘happiness’ originates from?
We can at least say that the (this is an opinion) that the mind / temperament / personality /
mood and therefore state of well-being all originate from brain.
The quality of neural circuits are not only due to the genes (it is a blueprint for our neural
circuits and personality etc), but also due to? What are examples? So, how are the complex
neural circuits in the brain created?
- Life circumstances.
- Stress, pre-post natal factors, parental factors, food, alcohol, drugs, activity, sport,
SES, education etc.
- So the genes and environment have complex interactions and that is how the
complex neural circuits in the brain are created.
You can view your brain as the contactpoint/hub with the world around us. Through what
pathways does this go?
Through sensory/motor pathways.
The brain creates behavior and thoughts. Also behavior influences the brain and thinking
influences brain. Additionally life circumstances, culture and the world influences the brain.
Our personality has relatively steady basic characteristics. What is one of the best models?
How are these personality traits shaped? (3)
- Big Five personality traits (five factor model [FFM])
- By genes, experience and age
What is the heritability of personality, what does this mean?
How much of your personality is created by genes?
,What are the five domains of the bigh five personality traits and what are there heritability
scores? (5) What is interesting to note?
1) Openness to experience (57%)
- (inventive/curious vs. consistent/cautious)
2) Conscientiousness (49%)
- (efficient/organized vs. easy-going/careless)
3) Extraversion (54%)
- (outgoing/energetic vs. solitary/reserved)
4) Agreeableness (42%)
- (friendly/compassionate vs. challenging/detached)
5) Neuroticism (48%)
- (sensitive/nervous vs. secure/confident)
→ It is interesting that all the traits hover around 50%, because this means that part of your
personality is hard to change.
What is heritability?
The proportion of variation in a population trait that can be attributed to inherited genetic
factors
We are not a ‘victim’ of our genes, meaning no genetic determinism. What does this
mean?
Our genes do not solely define our personality.
For MOST of us, there is a possibility to have an influence on brain, mind, personality, mood,
stress responsivity, impulsivity, well-being, life satisfaction (‘happiness’) to a certain degree.
But what is the case for some of us?
For SOME of us, underlying brain neural circuitry is too severely damaged / severe errors
neuronal networks, and therefore the people can not change that themselves without
medical/professional intervention.
There is no complete malleability of brain / behavior. What does this mean?
Not everybody can change their brain to the same degree or in the same way.
What is anhedonia?
Inability to experience pleasure.
Brain in constant interaction with our own behavior and the world around us. How is this
possible? (4)
Hormones
Autonomic nervous system
Stress System
Plasticity of brain circuits
,Hormones influence behavior. What brain structure is between the NS and the endocrine
system? What does this structure control?
- The brain structure hypothalamus.
- The pituitary gland (master gland of endocrine system).
Hypothalamus consist of different nuclei with different functions that will create hormones
that will be released onto the pituitary gland (master gland). What will the pituitary gland
now do? What will these hormones do?
- Release hormones in answer to that (e.g., oxytocin).
- These hormones will act on the glands in your body (thyroid stimulating hormone will
act on your thyroid).
Hormones act as transcription factors. What does this mean? What happens when you
influence this? What is the consequence of this?
- When the bind to the receptor, it will make the receptor relocate to the nucleus and
act as a transcription factor influencing gene expression.
- You then alter the amount and mix of proteins.
- Yu alter the function of the cell and in doing that you may alter behavior.
What is the ANS about?
Regulation of internal organs (smooth muscle, cardiac muscle) and glands.
ANS consist of two Divisions. What are the two divisions? (2) What NT is important for the
sympathetic and parasympathetic NS? (2) What are the functions? (2) Which nerves are
connected to the sympathetic NS?
1) Sympathetic (Noradrenaline)
- NT = Noradrenaline
- Arouses the body for action
- “Fight or Flight”
- [Spinal nerves in the thoracic and lumbar regions are connected to the sympathetic
ganglia]
2) Parasympathetic
- NT = Acetylcholine
- Calms the body down
- “Rest and Digest”
- [Connects with parasympathetic ganglia near target organs]
What happens if there is a strong increase in sympathetic activity? What happens if there is
a strong increase in parasympathetic activity? And with a balanced sympathetic and
parasympathethic activity?
- You may experience threat, stress, danger.
- You may experience calmness or even drowsiness.
- You may experience focus, ‘flow’
→ Most of the time we are in balance.
, To a certain degree, we can influence ANS. There are some behavioral interventions act via
ANS. The most well known is ‘breathing’. What is an example?
Inhaling activates the sympathetic NS and exhaling activates the parasympathetic NS.
Meaning, prolonging your exhale you can become more calm.
What is the fast-acting and slow-acting pathway from the stress-system? (2)
- Fast-acting pathway = ANS, sympathetic branch. Hypothalamus sends a neural
message to the spina lcord. The SNS is activated to stimulate the medulla of the
adrenal gland, which releases epinephrine into the circulatory system and this
activates the body’s cells.
- Slow-acting pathway = Endocrine system consisting of hypothalamus releasing
CRF into the pituitary gland, which releases ACTH into the cortex of the adrenal
gland, which releases cortisol into the circulatory system and activates the body’s
cells.
What is CRF? What is ACTH?
- CRF = Corticotropin-releasing factor
- ACTH = AdrinoCorticoTrophic Hormone
Corticol is a transcription factor which may alter gene expression. Why is it a functional
hormone?
Because you need it for alertness and focus.
What happens if you have a high level of sustained cortisol?
You can experience feelings of tension, stress, threat, depression, harmful effects
cardiovascular system and brain and suppression immune system.
→ It is important to keep our levels of cortisol at a functional level and not top high.
There is plasticity of the brain on various levels. What are they? (6)
- Neurogenesis (birth of new neurons, continues throughout adult life in hippocampus
and subventricular zone)
- Receptor adaptation: down/up regulation (creating more or less receptors),
(de)sensitisation (making receptors less or more sensitive), or the system can make
another other mix of receptors which influences the organism.
- Synaptogenesis (new synapses)
- Myelination
- Dentritic arborisation (increase in number and volume dendrites)
- Synaptic pruning (both axon and dendrite pruning, process of synapse elimination
between early childhood and puberty in mammals, including humans)
What is synaptic pruning?
Unnecessary pathways in the brain are pruned out and the one’s that are necessary are kept
in the brain.
We have a concept called functional plasticity. What is this?
- Shifting connections between different parts of the cortex.
