Neuroscience intro lecture
Front of brain is for motor movements; the back is sensory.
The connections in your brain are white (white matter due to myelin), the grey part of the brain is
where the cell bodies of the neurons are.
When stress levels are high, prefrontal cortex (planning) = pressured (make irrational decisions).
Small brain/ cerebellum = coordination of voluntary movement (you can train this).
Don’t eat greasy food = dentate, emboliform, globose and fastigi: the 4 cerebellar nuclei EXAM
QUESTION!
Basal ganglia are affected in Parkinson’s disease (problems with movement).
Neuroanatomy lecture 1
Neuron are the unit of a brain and make specific functions possible.
Oligodendrocytes ‘cause’ myelination in CNS and Schwann cells in PNS.
CNS = brain + spinal cord.
The PNS connects us to the environment (bridge between the CNS to the rest of the body).
Frontal cortex; cognitive functions and action.
Hemispheres (left and right) are connected by the corpus callosum.
The brain is covered by meninges; dura mater, arachnoid, pia mater layers, from lateral to medial
respectively. These layers are the first line of protection for brain and spinal cord, they protect the
brain against viruses, attacks, bacteria, etc.
Carotid and vertebral arteries go straight to the brain (oxygenated). Blood supply to the nervous
system directly from the heart go via carotis interna (supply to anterior part of the brain) and
vertebral artery (supply to posterior part of the brain). Blood is drained back via jugular vein.
Principal of redundancy in the circle of Willis; you double the vessels, so if one fails to work
properly (strokes), other vessels can take over the lack of function.
Ventricles are filled with cerebral spinal fluid; proteins, glucose, salt and ions. Takes nutrients to the
cells, allows the brain to swim in the skull (makes possible that this final volume/ weight is cut up).
Cushion/ buoyancy effect prevents damage of the brain in case of accidents/ weight.
Hydrocephalus, enlargement of skull because CSF does not flow back(?) via the sinuses.
Neuroanatomy lecture 2
Telencephalon: becomes the brain with the cortex, attributes the motor function of the body. Four
lobes: frontal, parietal, occipital and temporal (actually 6: insularic and limbic lobe, but you cannot
see these from the outside). And basal ganglia (caudatus, putamen and globus pallidus).
Diencephalon: the part that has all the important structures to survive (hypothalamus, thalamus
and epithalamus). The thalamus has grey matter and a y-shaped white matter. Genicolatum is
important for vision, EXAM QUESTION.
Mesencephalon: (midbrain) important for control of motions and motivation (and visual processing).
And substantia nigra, which looks like a moustache.
Metencephalon: contains the pons and the cerebellum, provides sensory innervation to the face
(also important for balance and coordination). Connects the brain with the spinal cord.
Myelencephalon: (afterbrain) is the most posterior region of the embryonic hindbrain. Same
function as the metencephalon. And medulla oblongata
Capillaries form 2 barriers: blood-brain barrier and blood-CSF barrier.
Grey matter is the residing place for the neurons going to the brain, especially the cortex has many
neurons (dendrites, non-myelinated). White matter is mostly the axons (ODC and myelin), this is the
connecting hump between the different brain regions/ cortex. No cell bodies in WM.
,Most important highways, 3 categories of fibers in the WM:
association - and commissural - and projection fibers.
In the spinal cord, dorsal is from the back and ventral is the belly side. The bridge between motor and
sensory is for reflexes.
In the spinal cord; more white matter inside, grey matter outside, so the other way around.
Dorsal root ganglions are neurons that receive information from the sensory organs (information
from the outside) to the medulla. Motor neurons travel from the brain via the ventral column to the
muscles.
When the baby is born, myelination (and synaptic pruning) is not completed yet because this continue
all the way till the adulthood.
Ventricles are filled with CSF which is produced in the choroid plexus.
The brain has 3 lines of protection: meninges, CSF and BBB. The role of astrocytes in the BBB is to
provide the neurons of nutrients (they also play a repair role). Blood-CSF barrier, together with BBB,
microglia and meninges, makes an efficient vault protection system.
Neuroanatomy lecture 3
Motor control is interconnected with sensory pathways.
- ascending pathway: (somato)sensory. Stimulus comes from the outside, reaches the sensory
organs (e.g. skin) > spinal cord > brain.
o medial lemniscus tract (gnostic quality, proprioception/ fine touch, enter the brain)
o anterolateral pathway (nociception/ pain, decussates already in the spinal cord)
- descending pathway: motor. Comes from the brain > through the cortex > muscle: contract
or relax.
o ventral corticospinal tract (ipsilateral): direct to the spinal cord
o lateral corticospinal tract: direct, decussation caudal medulla
o corticobulbar pathway (indirect): movement of head, neck and face
Primary motor cortex (M1): M1 and S1 are the primary cortices (in frontal and parietal lobe). They
are important for initiation of voluntary movement and an elaboration of somatosensory stimuli from
thalamus, respectively. These cortices have a homuncular organisation. Motor and sensory control
from cortex respect the contralateral body representation. The right motor cortex will control the left
part of our body and left will control right, due to a cross over (decussate) of the fibers at the level of
the brainstem/ pyramis.
Cross over by medulla oblangata (myelencephalon) is important to understand.
Association motor cortices: adaptive behaviour.
Primary visual cortex (V1) takes information from the eyes.
Visual perception takes 2 pathways:
- where pathway, tells you where the object is
- what pathway, recognizes based on experience, analysis of form and color, straight to
hippocampus
The frontal cortex is also an important association cortex, playing a role in decision making.
Which ones are association fibers? EXAM QUESTION!
Prefrontal cortex is a very important association cortex
Unimodel en multimodel?
There are 6 cortical layers in the neocortex, but the hippocampus only has 4 layers.
Temporal cortex = recognition.
Parietal cortex = attention.
Frontal cortex = planning.
, The most important structures in the cerebral cortex are pyramidal cells (except in the first layer).
Cells do not only divide into layers, they also pile up in a ‘cortical column’ where they share the same
receptive field.
Basal ganglia: group of cortical structures made up by different nuclei (= striatum, globus pallidus,
subthalamic nucleus, substantia nigra), they communicate a lot with the motor cortex.
Functions basal ganglia: initiation of movement, movement scaling (direct pathway allows excitation
of the motor cortex, indirect pathway allows inhibition of the motor cortex), movement sequencing,
switching movement, selection/ inhibition competing motor program.
Cerebellum: 3 parts (balancing and finetune movements possible):
Spino-cerebellum; allows coordination.
Vestibulo-cerebellum; oldest part, important for balance.
Cerebro-cerebellum; planning and timing of movement (cognitive function, like speech).
The cerebellum has 3 peduncles: superior, middle and inferior. Peduncles are the highways of the
axons to communicate with the rest of the brain (superior/ efferent and middle/ afferent) and the
spinal cord (inferior, afferent). EXAM QUESTION
Afferent is from the outside to the inside, efferent is from the inside to the outside.
Spinal cord
..(5 mentioned above) are involved in voluntary movement.
Parkinson’s: loss of dopamine neurons in substantia nigra, indirect pathway not inhibited anymore >
stop of movement. Problems in initiating the movements.
LIMBIC (border) SYSTEM: hippocampus and amygdala, for memories, emotions, and survival. The
limbic system is also involved in pathological behaviors like drug addiction.
Border between old and new brain.
Amygdala place for emotional control (front of hippocampus), can be divided in central/lateral and
central/ medial? Involved in: emotion, motivation, emotional behaviour, fear responses.
Hippocampus (declarative/ explicit memory?) and amygdala are the centre of the limbic system.
Malfunctions in these regions leads to pathological consequences:
HIP: Alzheimer’s disease, affects memory.
GB/BG: Huntington corea: unintentional coreoathetoid (competing) movements.
AMY: panic attack.
SN: Parkinson’s disease, problem in initiating movement.
CEREBELLUM: ataxia, lack of coordination voluntary movement.
Questions association cortex pre-recorded video:
Green = yes = prefrontal cortex.
Blue = no = corpus callosum.
Red = no = M1.
Grey = no = S1.
Orange = yes = V2.
Violet = no = thalamus.
