1. Last Lecture http://www.umich.edu/~psycours/345/
What is Cognitive Neuroscience?
Historical Roots
Phrenology
Modern Neuropsychology: Broca, Wernicke
Study of lesion effects: Prism on the mind
Experimental vs. clinical neuropsychology

2. Today’s Lecture Getting around the brain Orientational Terminology
Gross Neuroanatomy
Maps
Cytoarchitectonic
Projections Maps

3. Directional Terms

4. Planes of Section Frontal plane: coronal section
Sagittal plane : medial and parasagittal section
Horizontal plane: transaxial or horizontal section

5. Planes of Section
Frontal plane: coronal section

6. Planes of Section
Sagittal plane : medial & parasagittal section

7. Planes of Section
Horizontal plane: horizontal or transaxial section

8. Photo
PET

11. Major Subdivisions: Forebrain, Midbrain, Hindbrain
Medulla
Pons
Cerebellum
Midbrain
superior colliculus
inferior colliculus
Motor nuclei
Hindbrain:
medulla: motor nuclei of the cranial nerves
vital functions & reflexes: respiration, heart rate
reticular activating system
cerebellum: balance, timing, posture, coordinated movements, cognition??
pons: cranial nerves, superior olive (auditory nucleus) reticular activating system, vestibular nuclei for balance
Midbrain:
superior and colliculus, oculomotor nuclei

12. Major Subdivisions: Forebrain, Midbrain, Hindbrain
Medulla
Pons
Cerebellum
Midbrain
superior colliculus
inferior colliculus
Motor nuclei
Hindbrain:
medulla: motor nuclei of the cranial nerves
vital functions & reflexes: respiration, heart rate
reticular activating system
cerebellum: balance, timing, posture, coordinated movements, cognition??
pons: cranial nerves, superior olive (auditory nucleus) reticular activating system, vestibular nuclei for balance
Midbrain:
superior and colliculus, oculomotor nuclei

13. Forebrain
neocortex/cortex
limbic system
basal ganglia
olfactory system
thalamus / hypothalamus

14. Our primary focus: Neocortex
Phylogenetically youngest structure
Well developed only in mammals
Accounts for 9 billion of the 12 billion neurons in the human nervous system.

15. Terminology (for a convoluted surface)
Fissure: Deep cleft
Sulcus: Shallow cleft
Gyrus: Ridge
Major Landmarks
Longitudinal Fissure: separates Left & Right hemispheres
Central Fissure: separates parietal and frontal
Lateral (Sylvian) Fissure
dorsal boundary of temporal lobe

16. Four Lobes: Named for overlying skull bones
Offer "crude" functional (sensory-motor) parse
Frontal: voluntary motor control
Parietal: somatosensory
Temporal: auditory
Occipital: visual

18. Blood Supply to the Brain (highlights)
Internal Carotid arteries- supply only cortex
anterior cerebral artery
middle cerebral artery
Vertebral Arteries- supply brainstem, cerebellum and cortex
posterior cerebral artery
occipital, temporal lobes
tectum
Neurons are highly metabolic, thus sensitive to oxygen and glucose deprivation
Brain uses large fraction of body’s energy resources-- 20% of circulating glucose is used by brain.
PET, SPECT, fMRI are all sensitive to local changes in cerebral blood flow.
Arterial blood supply to the brain provides different territories of the brain with blood. If there is clogging or infarction, stroke then the regions of cortex supplied by the affected branch will be at risk.

20. Principles of Cortical Organization: Cytoarchitectonic Maps & Projection Maps
system for classifying & defining cortical organization
orderly representation on cortical surface
structural basis for defining an area's function
function can follow closely from structure (e.g. projection maps)

21. Nissl stain reveals cell bodies (rich in DNA and RNA)
Golgi stains reveals axons
White matter tracts carrying connections between brain regions:
cortical-cortical, cortical thalamic, thalamo-cortical.

22. Cytoarchitecture Gray matter is 2 mm thick.
6 layers differing in number, type, density of cells.
2 & 4 : receiving layers
fibers from sensory and association cortex
thicker in sensory cortex
3, 5 & 6: sending layers
3 association cortex and commissures
5 brainstem and spinal cord
6 thalamus
thicker in motor cortex
Thalamocortical, corticothalamic & Corticocortical connections (intra and interhemispheric)

23. Cytoarchitectonic Maps: Complex micro-structure of neural tissue
Brodmann's (1909) Map
Classified regions based on density of cell layers
Identified about 50 distinct areas
Structural classification --> functional differences
system widely used to refer to areas of interest.

24. Cytoarchitectonic Maps: Complex micro-structure of neural tissue
Brodmann's (1909) Map
Classified regions based on cell layers
Identified 52 areas
Structural classification --> functional differences
system widely used to refer to areas of interest.

25. Projection Maps defined by their input
What gets mapped depends on the sensory modality
vision-- visual space
auditory-- pitch (frequency)
touch-- body surface

26. Generic (simplified) Pathway:
Properties of Cortical
Organization
Hierarchical Organization
ranking based on modality specificity & complexity of functions
Contralateral Organization
e.g. LH represents:
Right Visual Field
Right side of body
Right Ear Input
Vice versa for RH
Functional Segregation
“modules” with specialized functions
Generic (simplified) Pathway:
SENSORY RECEPTOR
THALAMIC NUCLEUS
PRIMARY CORTEX
SECONDARY CORTEX
ASSOCIATION CORTEX
Association cortex- 75% of all brain tissue
thalamic input is via thalamic nuclei that get their input from other cortical areas, not from sensory receptors.
this input to association areas is highly processed and multi modal.