, Lecture 1
Basic Brain Anatomy
Statements
- We use all our neurons actively; long-term inactive neurons die due to a lack of neurotrophic
factors
- recently developed methods for cell counting have shown that in case of healthy, non-demented
elderly only limited loss of neurons occurs (max. 5%).
- (neurogenesis) still takes place at all ages, although the production is rather low at high age.
Physiology brain
Gyrus (hili): higher part of brain
Sulcus: grooves
Fissure (big curve)
History (phrenology)
Past ideas: shape of skull -> you can figure out a lot about someone (not anymore)
Now certain areas have specific functions
Language
Broca: problem speaking (motor aphasia)
Wernicke: can speak but not logically (sensory aphasia) (dyslexia)
Brain imaging
CT scan: computerized tomography (structure)
PET scan: positron emission (activity)
MRI scan: magnetic resonance imaging (structure) fMRI scan: functional MRI (activity)
,Psychopaths
Amygdala not as active
Orbital cortex (area which is responsible for
moral decision-making) not as active
-> cannot control amygdala (dictates •
aggression)
Fallon: people with not that much brain
activity, were psychopaths)
Sections
Orbital cortex
Dimensions neurons
Neuron cell bodies: 100 micro m
Large axons and dendrites: 10 micro m
Synaptic ending: 1 micro m
Synaptic cleft: 20 nano m
Neuronal membrane: 5 nano m
Diameter ion channel: 0.5 nano m
Kind of cells (white/ grey matter)
Gray matter: cell body + dendrites
-> Has many layers: some layers have cell bodies, and some have only dendrites
White matter: axons (majority)
-> Only consists of one layer
Microglia will get activated
when lesions takes place:
they try to fix it
, Ventricular system
Brain surrounded by CSF (cerebrospinal fluid) (fluid around brain)
Brain exists of 150 mL fluid (but 500 mL produced in the day (washes brain 3x)
- For protection and wash the brain (get rid of left over from activity)
Sleep has an important role in this
We have 4 ventricles: moves fluid through the brain
Fluid through cerebral aqueduct -> heart -> leaves body -> blockage in cerebral
aqueduct -> waterhead
1st an 2nd ventricle
are lateral
Neurophilosophy
Neuron a basic unit which can be studied by neuroanatomical techniques
In the cortex there are a lot of layers: denser in the middle
Staining
Analysis of brain material: Nissl staining (Franz Nissl)
->stain neurons and dendrites
Nissl thought neurons and dendrites were independent
Golgi staining (Camillo Golgi): Rival of Nissl still got a Nobel price
-> neurons and dendrites are connected
Cajal did microscopy: Dendrites and axons are indeed connected
For every neuron -> one axon (don’t have spines, only terminals)
It can have several dendrites
Basic Brain Anatomy
Statements
- We use all our neurons actively; long-term inactive neurons die due to a lack of neurotrophic
factors
- recently developed methods for cell counting have shown that in case of healthy, non-demented
elderly only limited loss of neurons occurs (max. 5%).
- (neurogenesis) still takes place at all ages, although the production is rather low at high age.
Physiology brain
Gyrus (hili): higher part of brain
Sulcus: grooves
Fissure (big curve)
History (phrenology)
Past ideas: shape of skull -> you can figure out a lot about someone (not anymore)
Now certain areas have specific functions
Language
Broca: problem speaking (motor aphasia)
Wernicke: can speak but not logically (sensory aphasia) (dyslexia)
Brain imaging
CT scan: computerized tomography (structure)
PET scan: positron emission (activity)
MRI scan: magnetic resonance imaging (structure) fMRI scan: functional MRI (activity)
,Psychopaths
Amygdala not as active
Orbital cortex (area which is responsible for
moral decision-making) not as active
-> cannot control amygdala (dictates •
aggression)
Fallon: people with not that much brain
activity, were psychopaths)
Sections
Orbital cortex
Dimensions neurons
Neuron cell bodies: 100 micro m
Large axons and dendrites: 10 micro m
Synaptic ending: 1 micro m
Synaptic cleft: 20 nano m
Neuronal membrane: 5 nano m
Diameter ion channel: 0.5 nano m
Kind of cells (white/ grey matter)
Gray matter: cell body + dendrites
-> Has many layers: some layers have cell bodies, and some have only dendrites
White matter: axons (majority)
-> Only consists of one layer
Microglia will get activated
when lesions takes place:
they try to fix it
, Ventricular system
Brain surrounded by CSF (cerebrospinal fluid) (fluid around brain)
Brain exists of 150 mL fluid (but 500 mL produced in the day (washes brain 3x)
- For protection and wash the brain (get rid of left over from activity)
Sleep has an important role in this
We have 4 ventricles: moves fluid through the brain
Fluid through cerebral aqueduct -> heart -> leaves body -> blockage in cerebral
aqueduct -> waterhead
1st an 2nd ventricle
are lateral
Neurophilosophy
Neuron a basic unit which can be studied by neuroanatomical techniques
In the cortex there are a lot of layers: denser in the middle
Staining
Analysis of brain material: Nissl staining (Franz Nissl)
->stain neurons and dendrites
Nissl thought neurons and dendrites were independent
Golgi staining (Camillo Golgi): Rival of Nissl still got a Nobel price
-> neurons and dendrites are connected
Cajal did microscopy: Dendrites and axons are indeed connected
For every neuron -> one axon (don’t have spines, only terminals)
It can have several dendrites
