Behavioural Neurosciences
1, Introduction:
The human brain has about 100 billions neurons, each connected to 10 thousand other neurons. But
even after hundreds of years of studying the brain, we still don’t understand numerous aspects of it.
False news:
- “At the age of 25, neurons start to die, and at a high age, a large number of neurons are gone.”
But maximal 5% of all neurons are lost, and this happens very slow. Only people with
neurpdegeneree disease, like Alzheimer, lose more neurons.
- “After birth and the first years of brain development, no new neuron are being born in the
brain.” In at least three regions of the brain, the production of new neurons still takes place at all
ages, although the production is rather low at high age.
- “We only use part of our brain”, but this is absolutely nonsense. We use all of our neurons
actively and neurons that are inactive for a long time, die.
Brain anatomy:
The nervous system consists of the central nervous system and the peripheral nervous system.
When we talk about the central nervous system, we mean the brain and the spine. When we talk
about the peripheral nervous system, we mean all the neurons that live outside the central, so the
neurons that take information from the limbs to the spine and visa versa.
On the brain we have sulcus and gyrus, by which
the sulcus are grooves in the brain and the gyrus
are hills.
The brain can be divided in four lobes;
Frontal lobe; voluntary movement, problem
solving and personality.
Parietal lobe; sensory perception, language
Occipital lobe; visual perception
Temporal lobe; processing auditory information,
with memory
Phrenology is the idea the shape of your head,
predicts your character, what you are good at and
whether you are a criminal. This is mostly false,
but there is some truth in it. The shape of your
forehead is related to our personality. However, some people have a very small brain but they can
still be smarter then other.
We can pinpoint certain brain regions and their functions, but they never work alone. For example,
Broca. He claimed what was wrong in the brain of his patient, and when the patient died, Broca
took the brain. He then saw a hole in the brain, which got then labeled the Broca’s Area. If this
area is damaged, it causes motor aphasia. This means they comprehend the audio, but the speak
output is greatly decreased. These people have trouble repeating words. So, more listening, less
talking.
Wernicke’s area is another area of which we know the function. Damage in this area can cause
sensory aphasia. This means that they cannot comprehend the auditory imputs, but can speak
fluently. These people are relatively okay with repeating words. So, more talking, less listening.
,Brain imaging:
We have several scans to use when we want to look at the brain;
CT scan (computerized
tomography),
MRI scan (Magnetic
resonance imaging), patient
doesn’t need to do anything.
, PET scan (position emission
tomography), patient needs to do
something.
fMRI scan (functional magnetic
resonance imaging), patient needs
to do something.
Using the PET scan, we were able to see the differences in the brain between normal people and
psychopath. The patients were shown disturbing pictures and the brain was observed. The frontal
lobe (responsible for empathy, among other things) and the visible cortex of the psychopath shows
low activity, in contrary to the high activity of normal people.
One scientist tested his own brain and found out, his was similar to the psychopath, so this is not a
bulletproof method.
Terminology:
Rostral/anterior= front
caudal/posterior= back
dorsal= top
ventral= bottom
lateral= away from the midline
medial= towards the midline
Grey matter: consists of the dendrites and the axon terminals of the neurons.
White matter: consists of the axons of the neurons.
So the action potential travels in from the grey matter through the white matter, to the grey area to
be send out. Though, this is not always the case.
, The neocortex consists of 6 layers, all in the grey matter. Each layer has a characteristic distribution
of different neurons and their connections with other cortical and subcortical regions.
Layer 2/3: regulates the communication between the cortical modules.
Layer 5/6; are important for cortical output.
Neurons are overrated, glial cells are better. A person has twice as many glial cells than neurons.
They are found in the both the peripheral nervous system and the central nervous system.
Peripheral: they are found as Schwann cells and satellite cells. The Schwann cells form the myelin
sheets around the axon in the peripheral nervous system.
Central; they are found as oligodendrocytes, astrocytes, microglia and ependymal cells. The
oligodendrocytes from the myelin cells around the axon in the central nervous system.
As for the function of the other types of cells, read below;
The brain consists of 4 ventricles. In the 3rd and 4th ventricles, CSF is produced.
CSF: cerebrospinal fluid. Around 500ml of CSF is produced every day, and about 150ml of CSF is
present in the ventricles at one time. This is a fluid that gets pumped through the brain and is
eventually guided out of the brain, if this doesn’t happen, its bad.
The CSF is a fluid that is used to wash out impurities of the brain, delivers nutrients (like glucose)
and provides protective barrier for the brain. It travels through the brain ventricles, in patients with
schizophrenia, these ventricles can be enlarged.
Neurophilosophy: is the study that studies the neuron as a basic unit by neuroanatomical
techniques. This does not require any mind-brain separation.
Staining: there are a battle going on, when staining was invented. It was between Nissl and Golgi.
Nissl’s technique consistently shows the the whole neuron population, but with very few detail.
Only the Nissl bodies can be seen, which are clumps of the endoplasmic reticulum, which is located
in the soma. On the contrary,
Golgi’s technique shows a detailed depicting of the neuron morphology, while the majority of
neurons remain unstained. This only depicts the axons of a neuron.
1, Introduction:
The human brain has about 100 billions neurons, each connected to 10 thousand other neurons. But
even after hundreds of years of studying the brain, we still don’t understand numerous aspects of it.
False news:
- “At the age of 25, neurons start to die, and at a high age, a large number of neurons are gone.”
But maximal 5% of all neurons are lost, and this happens very slow. Only people with
neurpdegeneree disease, like Alzheimer, lose more neurons.
- “After birth and the first years of brain development, no new neuron are being born in the
brain.” In at least three regions of the brain, the production of new neurons still takes place at all
ages, although the production is rather low at high age.
- “We only use part of our brain”, but this is absolutely nonsense. We use all of our neurons
actively and neurons that are inactive for a long time, die.
Brain anatomy:
The nervous system consists of the central nervous system and the peripheral nervous system.
When we talk about the central nervous system, we mean the brain and the spine. When we talk
about the peripheral nervous system, we mean all the neurons that live outside the central, so the
neurons that take information from the limbs to the spine and visa versa.
On the brain we have sulcus and gyrus, by which
the sulcus are grooves in the brain and the gyrus
are hills.
The brain can be divided in four lobes;
Frontal lobe; voluntary movement, problem
solving and personality.
Parietal lobe; sensory perception, language
Occipital lobe; visual perception
Temporal lobe; processing auditory information,
with memory
Phrenology is the idea the shape of your head,
predicts your character, what you are good at and
whether you are a criminal. This is mostly false,
but there is some truth in it. The shape of your
forehead is related to our personality. However, some people have a very small brain but they can
still be smarter then other.
We can pinpoint certain brain regions and their functions, but they never work alone. For example,
Broca. He claimed what was wrong in the brain of his patient, and when the patient died, Broca
took the brain. He then saw a hole in the brain, which got then labeled the Broca’s Area. If this
area is damaged, it causes motor aphasia. This means they comprehend the audio, but the speak
output is greatly decreased. These people have trouble repeating words. So, more listening, less
talking.
Wernicke’s area is another area of which we know the function. Damage in this area can cause
sensory aphasia. This means that they cannot comprehend the auditory imputs, but can speak
fluently. These people are relatively okay with repeating words. So, more talking, less listening.
,Brain imaging:
We have several scans to use when we want to look at the brain;
CT scan (computerized
tomography),
MRI scan (Magnetic
resonance imaging), patient
doesn’t need to do anything.
, PET scan (position emission
tomography), patient needs to do
something.
fMRI scan (functional magnetic
resonance imaging), patient needs
to do something.
Using the PET scan, we were able to see the differences in the brain between normal people and
psychopath. The patients were shown disturbing pictures and the brain was observed. The frontal
lobe (responsible for empathy, among other things) and the visible cortex of the psychopath shows
low activity, in contrary to the high activity of normal people.
One scientist tested his own brain and found out, his was similar to the psychopath, so this is not a
bulletproof method.
Terminology:
Rostral/anterior= front
caudal/posterior= back
dorsal= top
ventral= bottom
lateral= away from the midline
medial= towards the midline
Grey matter: consists of the dendrites and the axon terminals of the neurons.
White matter: consists of the axons of the neurons.
So the action potential travels in from the grey matter through the white matter, to the grey area to
be send out. Though, this is not always the case.
, The neocortex consists of 6 layers, all in the grey matter. Each layer has a characteristic distribution
of different neurons and their connections with other cortical and subcortical regions.
Layer 2/3: regulates the communication between the cortical modules.
Layer 5/6; are important for cortical output.
Neurons are overrated, glial cells are better. A person has twice as many glial cells than neurons.
They are found in the both the peripheral nervous system and the central nervous system.
Peripheral: they are found as Schwann cells and satellite cells. The Schwann cells form the myelin
sheets around the axon in the peripheral nervous system.
Central; they are found as oligodendrocytes, astrocytes, microglia and ependymal cells. The
oligodendrocytes from the myelin cells around the axon in the central nervous system.
As for the function of the other types of cells, read below;
The brain consists of 4 ventricles. In the 3rd and 4th ventricles, CSF is produced.
CSF: cerebrospinal fluid. Around 500ml of CSF is produced every day, and about 150ml of CSF is
present in the ventricles at one time. This is a fluid that gets pumped through the brain and is
eventually guided out of the brain, if this doesn’t happen, its bad.
The CSF is a fluid that is used to wash out impurities of the brain, delivers nutrients (like glucose)
and provides protective barrier for the brain. It travels through the brain ventricles, in patients with
schizophrenia, these ventricles can be enlarged.
Neurophilosophy: is the study that studies the neuron as a basic unit by neuroanatomical
techniques. This does not require any mind-brain separation.
Staining: there are a battle going on, when staining was invented. It was between Nissl and Golgi.
Nissl’s technique consistently shows the the whole neuron population, but with very few detail.
Only the Nissl bodies can be seen, which are clumps of the endoplasmic reticulum, which is located
in the soma. On the contrary,
Golgi’s technique shows a detailed depicting of the neuron morphology, while the majority of
neurons remain unstained. This only depicts the axons of a neuron.
