General basics
Een embryo heeft een grote hindbrain en midbrain. Een volwassene heeft een grote forebrain.
Mammal brain comparison → frontal and prefrontal cortex of human is developed during
evolution.
Regions that are closer to the spinal cord → important for basal fundamental functions of the
organisms Regions that are closer to the forebrain → important for decision making
• Becomes large in development
Body planes:
- Radial symmetrically
- Bilateral symmetrically
Decision making
Circulating, digestion, breathing
Cerebral cortex: - Bestaat uit vier delen:
- Frontal: decision making BROCA
- Parietal: (somato)sensory
- Occipital: vision
- Temporal: hearing, speach, memory, smell WERNICKE
hippocampus for learning and memory (short term, process called acquisition)
retrieval when you memorize something the day after (cortex and
hippocampus used)
(- Insular: taste, visceral, feelings)
- Essential for consciousness (mind)
Het brein bestaat uit vier STRUCTUREN:
1. Brainstem - Two main functions:
- Basic funtions
- Sensory/motor nerves (filtering and routing info)
- Three structures:
- Medulla oblongata
- Pons
- Midbrain
2. Cerebellum - Two functions:
- Motor coordination, like walking
- Motor memory, like riding a bike after a very long time
- Voluntary movements! learning how to bike
- Also called ‘arbor vitae’ (tree of life)
- Right part of cerebellum communicates with:
The right part of the spinal cord
The left part of cortex
- Ataxia is a cerebellum disfunction
3. Thalamus
- All information from spinal cord goes through
- Thalamus: sorts data
,- Hypothalamus: thermoregulation
- Pituitary gland: hormonal activity (oxytocin, water balance)
4. Cerebrum
- For integration triggers action or emotion
- White matter: fibers
- Reality: understand pictures and like or dislike them
- MRI: structural magnetic resonance imaging
- See thickness grey matter (cell bodies and neurons are located here) and see brain
activity
- fMRI: functional magnetic resonance imaging, measures changes in blood flow
- Ipsilateral hemisphere: on same side
- Contralateral hemisphere: on opposite site
- DTI: Measures microscopic movement of water in the brain
- Integrity of the white matter and numbers of fibers stroke
- Example: Corticospinal tract damage causes loss of movement ability
- Language-based activity: women use both sides of their brain whereas men use only a
single side. This difference may reflect different strategies used for language processing.
5. Cerebral cortex
• Consists of five parts
– Frontal cortex (about 50%)
– Parietal cortex (somatosensoric)
– Occipital cortex (vision)
– Temporal cortex (smell)
– Insular cortex (taste, visceral, feelings)
• Six-layered sheet (about 5 mm thick)
– Processing units (mini-columns)
– Primary sensory (topographical)
– Association parts (relates info)
• Total covers threequarters of brain
• Essential for consciousness (mind)
6. Corpus collosum
- Connects the left and right hemisphere by fibers (white matter).
Right hemisphere → facial recognition
Left hemisphere → reasoning, logic
- Brain areas that are involved in language → Broca’s (B), Geschwind’s (G), and Wernicke’s
(W) neocortical areas
• BROCA’S (B) area is only in left hemisphere: speaking, language produced
• GESCHWIND’S (G) area is in both hemispheres
• WERNICKE’S (W) area is in both hemispheres: language understood
7. Basal ganglia
- Involuntary movements.
- Diseases:
• Huntington disease
• Parkinson disease
- consists of caudate, putamen, globus pallidus and nucleus accumbens (Function: Reward
seeking behavior, pleasure, and addiction)
8. Midbrain- Substantia nigra
- Function: dopamine production
Disease:
• Parkinson disease neurons are dying (produce
,dopamine)
- component of substantia nigra is the black dark pigmented neuromelanin
9. Hippocampus
- CA1, CA2, CA3 areas → learning and memory
- In temporal lobe.
- Hippocampus in Alzheimer’s disease hippocampus is reduced.
- Hippocampus ischemia loss of neurons
POTENTIAL QUESTIONS
• What is the role of frontal cortex?
• What is the function of nucleus accumbens?
• Which neurotransmitter is produced by cells localized in substantia nigra? What is the
component of the SN neurons?
• What is the function of hippocampus? Which diseases are associated with loss of neurons in
hippocampus?
1. Primary Forebrain of the lamprey
• Dominant olfactory bulb
• Forebrain: only a small hemisphere
– Striatum pallidum brainstem
– GPh habenula brainstem
• Thalamus
• Medial pallium (precursor of hippocampus)
• Hypothalamus (output) |
• Upper brainstem (output)
– Motor output
– Monoaminergic feedback
1. Behaviour regulated by the primary brain
• Two essential forces necessary for survival of the individual and species
– Motivation to obtain food, water, warmth, comfort (reward driven)
– Motivation to escape from threat, heat, cold (misery driven)
• Very ancient mechanisms regulating behaviour (regulated by primary forebrain)
• Amygdala, hippocampus, hypothalamus, habenula
2. Secondary forebrain of the frog
• Larger hemispere
– No cerebral cortex
– Ventral striatum extrapyramidal system
– Pallium similar to the limbic system
– Rest amygdaloid complex
• Centromedial nucleus = striatum
2. Behaviour regulated by the secondary brain
• Intensity of reward driven behaviour
– Nc accumbens core – Anhedonia (lack of pleasure)
• Intensity of distress avoiding behaviour
– Nc acumbens shell – Dysphoria (feeling unhappy)
3. Tertiary forebrain of rhesus monkey
• Small olfactory bulb
• Appearance of cerebral cortex (early mammals)
– Frontal lobe
– Parietal lobe
– Occipital lobe
– Temporal lobe
• Basal ganglia
, • Cerebellum
• Small brainstem
3. Behaviour regulated by the tertiary brain
• Cerebral cortex (dorsal thalamus)
• Dorsal extrapyramidal system
• Consciousness
• Perception
• Language – Speech – Reading – Writing
• Inhibition of emotional response (primary forebrain)
• Execution of voluntary response
– Initiation, planning and execution
– Working memory
• Controlling motor response
Forebrain of humans
• Tertiary forebrain (mammal)
– Cerebral cortex
– Dorsal extrapyramidal system
• Secundary forebrain (frog)
– Limbic cortex
– Ventral extrapyramidal system
• Primary forebrain (lamprey)
– Hippocampus
– Amygdaloid complex
– Septal nuclei
– Hypothalamus
– Habenula
• Brain stem
– Midbrain
– Pons
– Medulla oblongata
• Cerebellum
• Spinal cord
– Cervical, thoracal, lumbal, sacral, coccygeal
PHYSIOLOGY OF SPECIFIC BRAIN REGIONS
- dorsal versus ventral functions
- lower versus higher functions
- cortical versus subcortical functions
1. DORSAL VERSUS VENTRAL
• Dorsal spinal cord and posterior cerebral cortex
– Afferent sensory root of spinal nerve (dorsal root)
– Ascending tracts of spinal cord
– Cerebral processing of sensory input
• Ventral spinal cord and anterior (frontal) cerebral cortex
– Efferent motor root of spinal nerve (musculoskeletal)
– Preganglionic autonomic nervous system
– Descending tracts of spinal cord
– Cerebral generation of behavioural output
2. LOWER VERSUS HIGHER
• Spinal cord
– Specific motor and autonomic control centres
• Central motor pattern generator
