Lecture 1 + 2 Introduction to Nutritional Neuroscience 1
Food is necessary for survival. However, it’s quite challenging for the body to
maintain homeostasis this is a primary brain function. The brain strives to
automate responses & minimize cognitive “interference”. You practically eat with
your brain to make food decisions.
The brain is part of the human nervous system:
Central nervous system (CNS)
o Brain
o Spinal cord includes cranial nerves (=ascending and descending
white matter tracts) conducts the final motor signals to muscles,
and takes in sensory information from the body’s peripheral sensory
receptors and relays it to the brain.
Peripheral nervous system (PNS) = everything outside the CNS
o Autonomic nervous system (controls function of organs and glands)
Parasympathetic rest & digest, maintenance by
acetylcholine
Sympathetic action by norepinephrine
o Somatic nervous system (transmits sensory and motor signals to
and from the CNS)
The has a lot of blood vessels, including the microvasculature 20% of the blood
flowing from the heart is pumped to the brain. The vertebral artery supplies
blood to the caudal portion of the brain, the internal carotid artery supplies
blood to the rostral portions Circle of Willis = provides a collateral blood flow
between the anterior and posterior arterial systems of the brain. Additionally, it
offers the alternate blood flow pathways between the hemispheres.
LET OP! Increasing blood flow is not primarily for increasing the delivery of
oxygen and glucose to the active tissue, but rather to hasten the removal of the
resultant metabolic by-products of the increased neuronal activity.
Blood brings 3 things to the brain: 1) Glucose (=primary fuel) 2) Oxygen 3)
Signalling molecules / hormones
Brain anatomy
Brainstem consists of midbrain, pons and medulla
Functions are reward processing, processing of gut signals and control of
heart and breathing rate
Receives/processes multiple GI signals
Connects with cortex, limbic system, thalamus and hypothalamus
Hindbrain = pons + medulla
The midbrain has autonomic functions substantia nigra and ventral
tegmental area (VTA) contain dopamine neurons which play a role in the
reward circuit moreover, contains neurons that participate in visuomotor
functions, visual reflexes and auditory relays
1
, The pons serves as coordination centre between the two hemispheres
The medulla is continuous with the spinal cord
LET OP! Does not regulate motor control.
Cerebellum (small brain)
Large neuronal structure overlying the brain stem at the level of the pons
Key to maintaining posture, walking, and performing coordinated
movements. LET OP! By itself, it does not control movements directly,
instead it integrates information about the body and motor commands and
modifies motor outflow to effect smooth, coordinated movements
outputs to the thalamus; (pre)motor complex
Cognitive functions and feeding control is under investigation, mounting
evidence may link somatic and visceral systems
Deep nuclei & internal white matter
Forebrain consists of cerebral cortex, basal ganglia and diencephalon
(thalamus & hypothalamus)
Cerebral cortex has 2 symmetrical hemispheres and is divided into 4/5 lobes.
The left and right cerebral hemispheres are separated by the longitudinal
fissure.
o Frontal lobe planning and execution of movements
o Parietal lobe touch, pain, temperature, limb proprioception
o Temporal lobe auditory processing
o Occipital lobe visual processing
o Limbic lobe / limbic system emotional processing,
learning, memory
LET OP! The central sulcus divides the frontal lobe from the
parietal lobe, and the lateral fissure separates the temporal
lobe from the frontal and parietal lobes.
The cerebral cortex contains the cell bodies of neurons, their
dendrites and some axons. It also contains blood vessels.
- Gray matter = neuronal cell bodies OUTSIDE
- White matter = axons (white because of fatty myelin coat) INSIDE
The cerebral cortex can be subdivided into major regions that differ based on
the degree of complexity of the neuronal layering. It can be divided into the
neocortex (six layers), mesocortex (paralimbic region) and allocortex (1-4
layers).
- The volume of neocortex that is not sensory or motor has traditionally
been termed the association cortex composed of regions that receive
inputs from one or more modalities.
LET OP! The folds of the human cortex serve a functional purpose: to pack
more cortical surface into the skull. Moreover, neurons are brought into closer
3D relationships to one another, saving axonal distance and neural conduction
time.
2
, Under each lobes basal ganglia are located
Diencephalon:
→ Thalamus
Relay of sensory info to cortex (exception: olfaction) “gateway to
cortex” because, except for olfaction, all sensory modalities make
synaptic relays in the thalamus before continuing to the primary
cortical sensory areas
Lateral geniculate nucleus visual
Medial geniculate nucleus auditory
Ventral posterior nuclei somatosensory
→ Hypothalamus
Homeostasis controls autonomic nervous system and endocrine
system (produces hormones)
Integration of neural and hormonal signals releases many hormones
and is sensitive to many hormones
Controls pituitary gland (vasopressin, oxytocin)
Energy intake regulation, hunger, satiety & thirst sensitive to
glucose
Stress
Sleep-wake, biorhythm
Forebrain: Cerebral cortex
Frontal lobe – motor areas
Planning and execution of movements
Stimulus evaluation, decision making
Motor cortex: contain motor neurons whose axons extend to the spinal
cord and brainstem and synapse on motor neurons in the spinal cord
Prefrontal cortex: takes part in the higher aspects of motor control and
planning and execution of behaviour, tasks that require integration of
information over time
o Orbitofrontal cortex extends to limbic lobe structures, maintain
interconnectivity
o Dorsolateral prefrontal cortex working memory functions
o Medial prefrontal cortex
Parietal lobe – somatosensory areas
Somatosensory processing responds to changes at the surface or inside
the body and controls “bodily sensations” (touch, pain, temperature). Two
main pathways:
o Anderolateral system: for pain and temperature sense
o Lemniscal system: touch, proprioception and movement
3
, Somatosensory inputs projecting to the parietal cortex arise from SI and SII
Visual processing dorsal pathway: from V1 (in occipital lobe) to
parietal lobe
o “where” / stimulus motion and localization within visual space
Temporal lobe – auditory processing
Auditory processing; contains auditory cortex (AI) & auditory association
area (AII)
Visual processing ventral pathway: from V1 (in occipital lobe) to
temporal lobe
o “what” / objects form and identity
Occipital lobe – visual processing
Visual processing
Visual cortex is effectively hidden from view, between the two
hemispheres
Visual information is processed by multiple cell layers in the retina and
transmitted via the optic nerve to the lateral nucleus of the thalamus, and
hence to primary visual cortex (V1) = primary visual pathway
Limbic lobe / system (5th ‘lobe’)
Several structures that form a border around the
brain stem
Emotion, learning, motivation, autonomic functions
Associated areas include basal ganglia (“reward”),
orbitofrontal cortex and piriform cortex (smell)
Hippocampus:
o Has the same shape as a “sea horse”
o Formation of memories
o Forming associations; (dietary) learning
o Spatial navigation (ruimtelijke orïentatie)
Amygdala:
o Controls autonomic, emotional and sexual behaviour
o Fear, arousal – emotion (unpleasant as well as pleasant)
o Couples learned cues to adaptive response
o “Valence” (relevance) = hunger modulates amygdala response to
food stimuli
Basal ganglia:
o Motor control; control of movement
4
Food is necessary for survival. However, it’s quite challenging for the body to
maintain homeostasis this is a primary brain function. The brain strives to
automate responses & minimize cognitive “interference”. You practically eat with
your brain to make food decisions.
The brain is part of the human nervous system:
Central nervous system (CNS)
o Brain
o Spinal cord includes cranial nerves (=ascending and descending
white matter tracts) conducts the final motor signals to muscles,
and takes in sensory information from the body’s peripheral sensory
receptors and relays it to the brain.
Peripheral nervous system (PNS) = everything outside the CNS
o Autonomic nervous system (controls function of organs and glands)
Parasympathetic rest & digest, maintenance by
acetylcholine
Sympathetic action by norepinephrine
o Somatic nervous system (transmits sensory and motor signals to
and from the CNS)
The has a lot of blood vessels, including the microvasculature 20% of the blood
flowing from the heart is pumped to the brain. The vertebral artery supplies
blood to the caudal portion of the brain, the internal carotid artery supplies
blood to the rostral portions Circle of Willis = provides a collateral blood flow
between the anterior and posterior arterial systems of the brain. Additionally, it
offers the alternate blood flow pathways between the hemispheres.
LET OP! Increasing blood flow is not primarily for increasing the delivery of
oxygen and glucose to the active tissue, but rather to hasten the removal of the
resultant metabolic by-products of the increased neuronal activity.
Blood brings 3 things to the brain: 1) Glucose (=primary fuel) 2) Oxygen 3)
Signalling molecules / hormones
Brain anatomy
Brainstem consists of midbrain, pons and medulla
Functions are reward processing, processing of gut signals and control of
heart and breathing rate
Receives/processes multiple GI signals
Connects with cortex, limbic system, thalamus and hypothalamus
Hindbrain = pons + medulla
The midbrain has autonomic functions substantia nigra and ventral
tegmental area (VTA) contain dopamine neurons which play a role in the
reward circuit moreover, contains neurons that participate in visuomotor
functions, visual reflexes and auditory relays
1
, The pons serves as coordination centre between the two hemispheres
The medulla is continuous with the spinal cord
LET OP! Does not regulate motor control.
Cerebellum (small brain)
Large neuronal structure overlying the brain stem at the level of the pons
Key to maintaining posture, walking, and performing coordinated
movements. LET OP! By itself, it does not control movements directly,
instead it integrates information about the body and motor commands and
modifies motor outflow to effect smooth, coordinated movements
outputs to the thalamus; (pre)motor complex
Cognitive functions and feeding control is under investigation, mounting
evidence may link somatic and visceral systems
Deep nuclei & internal white matter
Forebrain consists of cerebral cortex, basal ganglia and diencephalon
(thalamus & hypothalamus)
Cerebral cortex has 2 symmetrical hemispheres and is divided into 4/5 lobes.
The left and right cerebral hemispheres are separated by the longitudinal
fissure.
o Frontal lobe planning and execution of movements
o Parietal lobe touch, pain, temperature, limb proprioception
o Temporal lobe auditory processing
o Occipital lobe visual processing
o Limbic lobe / limbic system emotional processing,
learning, memory
LET OP! The central sulcus divides the frontal lobe from the
parietal lobe, and the lateral fissure separates the temporal
lobe from the frontal and parietal lobes.
The cerebral cortex contains the cell bodies of neurons, their
dendrites and some axons. It also contains blood vessels.
- Gray matter = neuronal cell bodies OUTSIDE
- White matter = axons (white because of fatty myelin coat) INSIDE
The cerebral cortex can be subdivided into major regions that differ based on
the degree of complexity of the neuronal layering. It can be divided into the
neocortex (six layers), mesocortex (paralimbic region) and allocortex (1-4
layers).
- The volume of neocortex that is not sensory or motor has traditionally
been termed the association cortex composed of regions that receive
inputs from one or more modalities.
LET OP! The folds of the human cortex serve a functional purpose: to pack
more cortical surface into the skull. Moreover, neurons are brought into closer
3D relationships to one another, saving axonal distance and neural conduction
time.
2
, Under each lobes basal ganglia are located
Diencephalon:
→ Thalamus
Relay of sensory info to cortex (exception: olfaction) “gateway to
cortex” because, except for olfaction, all sensory modalities make
synaptic relays in the thalamus before continuing to the primary
cortical sensory areas
Lateral geniculate nucleus visual
Medial geniculate nucleus auditory
Ventral posterior nuclei somatosensory
→ Hypothalamus
Homeostasis controls autonomic nervous system and endocrine
system (produces hormones)
Integration of neural and hormonal signals releases many hormones
and is sensitive to many hormones
Controls pituitary gland (vasopressin, oxytocin)
Energy intake regulation, hunger, satiety & thirst sensitive to
glucose
Stress
Sleep-wake, biorhythm
Forebrain: Cerebral cortex
Frontal lobe – motor areas
Planning and execution of movements
Stimulus evaluation, decision making
Motor cortex: contain motor neurons whose axons extend to the spinal
cord and brainstem and synapse on motor neurons in the spinal cord
Prefrontal cortex: takes part in the higher aspects of motor control and
planning and execution of behaviour, tasks that require integration of
information over time
o Orbitofrontal cortex extends to limbic lobe structures, maintain
interconnectivity
o Dorsolateral prefrontal cortex working memory functions
o Medial prefrontal cortex
Parietal lobe – somatosensory areas
Somatosensory processing responds to changes at the surface or inside
the body and controls “bodily sensations” (touch, pain, temperature). Two
main pathways:
o Anderolateral system: for pain and temperature sense
o Lemniscal system: touch, proprioception and movement
3
, Somatosensory inputs projecting to the parietal cortex arise from SI and SII
Visual processing dorsal pathway: from V1 (in occipital lobe) to
parietal lobe
o “where” / stimulus motion and localization within visual space
Temporal lobe – auditory processing
Auditory processing; contains auditory cortex (AI) & auditory association
area (AII)
Visual processing ventral pathway: from V1 (in occipital lobe) to
temporal lobe
o “what” / objects form and identity
Occipital lobe – visual processing
Visual processing
Visual cortex is effectively hidden from view, between the two
hemispheres
Visual information is processed by multiple cell layers in the retina and
transmitted via the optic nerve to the lateral nucleus of the thalamus, and
hence to primary visual cortex (V1) = primary visual pathway
Limbic lobe / system (5th ‘lobe’)
Several structures that form a border around the
brain stem
Emotion, learning, motivation, autonomic functions
Associated areas include basal ganglia (“reward”),
orbitofrontal cortex and piriform cortex (smell)
Hippocampus:
o Has the same shape as a “sea horse”
o Formation of memories
o Forming associations; (dietary) learning
o Spatial navigation (ruimtelijke orïentatie)
Amygdala:
o Controls autonomic, emotional and sexual behaviour
o Fear, arousal – emotion (unpleasant as well as pleasant)
o Couples learned cues to adaptive response
o “Valence” (relevance) = hunger modulates amygdala response to
food stimuli
Basal ganglia:
o Motor control; control of movement
4
