Summary Nutritional Neurosciences (HNH-51306)

Nutritional Neurosciences- Learning goals

Lecture 1+2- introduction to nutritional neuroscience 1

Brainstem
- Midbrain (autonomic functions: breathing, heart rate, swallowing)
- Pons
- Medulla
- Functions
 Reward processing: substantia/VTA contain dopamine neurons=reward circuit; midbrain
 Processing GI-signals
 Control heart/breathing rate

Cerebellum
- Motor control
- Cognitive functions, mounting evidence
- Feeding control, mounting evidence
- May link somatic and visceral systems= under investigation

Forebrain
- Cerebral cortex
 Frontal lobe: stimulus evaluation, decision making, controlling movement, planning
behaviour
-subparts: orbitofrontal cortex, dorsolateral prefrontal cortex, medial prefrontal cortex
 Parietal lobe: somatosensory processing, control bodily sensations, visual
processing(dorsal stream=where)
 Temporal lobe: auditory processing, visual processing(ventral stream=what),
hippocampus(limbic area)
 Occipital lobe: visual processing
 Insular cortex: hidden in lateral sulcus, concealed by parts of frontal, parietal and
temporal lobes
-anterior insula: olfactory, gustatory and limbic function, subjective feelings
-posterior insula: perception of bodily sensations: pain, visceral sensations, gastric
distension
 Limbic system: subcortical, emotion, learning, motivations, autonomic functions
-amygdala: controls autonomic, emotional and sexual behaviour, emotion, relevance of a
stimulus
-hippocampus: medial temporal lobe, formation of memories, forming associations,
learning, spatial navigation
-hypothalamus: homeostasis, integration with hormones, energy intake regulation, thirst,
hunger, stress, sleep

- basal ganglia: motor control, reward processing
 Striatum=putamen+pallidum+caudate; dorsal/ventral striatum nucleus
accumbens=hedonic hotspot
- diencephalon
 Thalamus: sensory relay
 Hypothalamus: sensitive to glucose/blood borne hormones(insulin, leptin, ghrelin)

Spinal cord central nervous system+brain

,Peripheral nervous system
- Sensory perception, nutrient sensing
- Most relevant nerves: sensory nerves in head and vagus nerve X
- Autonomic and somatic
 Autonomic nervous system
-Parasympathetic: rest and digest/maintenance, acetylcholine
-Sympathetic: action(fight/flight/freeze), norepinephrine
-Enteric nervous system


The chemical senses
-vision
 Cranial nerve II
 Thalamic nuclei
 Primary and secondary visual cortex in occipital and temporal/parietal lobe
 Attention is modulated by frontal cortex
 Looking at food: visual cortex, posterior insula, amygdala, orbitofrontal cortex
- Olfaction
 Olfactory nerve CN I
 Olfactory bulb= a tract
 Piriform cortex
 Orbitofrontal cortex(insula, amygdala, hippocampus, striatum, thalamus, hypothalamus)
 Flavour= retronasal odor+taste; multimodal integration sweet odor: anterior insula
- Gustation
 Tongue taste buds, receptor cells
 CN VII facial, IX glossopharyngeal, X vagus
 Nucleus solitary tract(NTS, brainstem) located in dorsomedial medulla(reflexes), first
relay station for visceral and taste afferents carried by cranial nerves
 Brainstem(NTS), thalamus, anterior insula/frontal operculum(primary taste cortex),
amygdala, prefrontal cortex
- Trigeminal sense
 CN V
 Pain
 Brainstem, thalamus
 Somatosensory cortex
 Limbic system, insula, OFC
- Vagus nerve X
 Innervates: mouth, throat
 GI tract
 Liver, kidneys
 Gut-brain highway




Indicate location brain structures

, - Medial= near the midline
- Lateral= near the outer edge
- Dorsal/superior= bovenkant; ventral/inferior=onderkant
- Caudal/posterior= achterkant; rostral/anterior= voorkant
- Slice orientation
 Transverse=axial: van linksrechts, voorachter doormidden
 Coronal=links rechts, bovenonder doormidden
 Sagittal=voorachter doormidden

-Tailarach/MNI space used for fMRI to align the images

- nomenclature Brodmann areas



Lecture 3+4- MRI and fMRI

MRI= magnetic resonance imaging
- No radiation
- Basic ingredients
 Static magnetic field(0.5-9.4 Tesla)
 Radiofrequency pulses(RF)
 Magnetic gradients(mT)
- Physics
 Rotating electrical charge= magnetic field; atoms with odd number of protons/neurons
spin inn a magnetic field
 Larmor frequency= all protons(1H) precess at same frequency in magnetic field
 Nuclei of some elements can absorb and re-emit radio frequency energy when in
magnetic field
 The magnetic field in the scanner causes the (hydrogen)nuclei to align with the direction
of the field; parallel(low-energy) or anti-parallel(high-energy)
 In the end there is a net magnetization in the directions of the magnetic field
 By sending in a RF pulse at a specific frequency we can selectively energize the hydrogen
nuclei(excitation)
 Apply gradients: differences in strength of magnetic field, to create in image
 Echo time(TE)= time between excitation and relaxation
 Repetition time(TR)= wait time until excitation is repeated
 T1 and T2 are tissue specific relaxation times of the MRI signal, it gives different contrasts.
T1= white, T2=dark
- Align
 Nuclei align to static magnetic field
 Nuclei precess at Larmor frequency
- Flip(excitation)
 A radiofrequency(RF) pulse at the Larmor frequency will be absorbed
 Spins are tilted(flipped)
- Relax
 Nuclei re-align to static field
 Emit RF at the Larmor frequency
 This signal is measured with a coil