Cerebral Cortex Flashcards
Vesalius
Stole beheaded heads and studied them
Father of anatomy
1543
First guy who ever decided to dissect stuff and actually look at what is happening
How much of the human brain (percent) is comprised of C.C?
80%
Is cerebral cortex axons or cell bodies?
Cell bodies
Thickness of cortex
2-4 mm
Organization of C.C between mamals
Preserved and same
Difference between human C.C versus animal C.C
Human CC is much larger and expanded and taken over more functions and space
Gyri
Folds in cortex
Sulci(fissures)
Grooves between folds
Does CC show variability in it’s structure?
Yes
3 prominent sulcuses from top of brain
Pre-central sulcus
Central sulcus
Post-central sulcus
Lateral sulcus
Divides frontal lobe and a bit of the parietal lobe from the temporal lobe
Central sulcus
Divides frontal lobe and parietal lobe
Longitudinal fissure
Separates the 2 cerebral hemispheres
Mid sagittal cut of brain exposes which part of cortex…
Limbic lobe
What bounds the limbic lobe?
Cingulate sulcus
Corpus collosum
Connects 2 cerebral hemispheres
Huge sheet of axons connecting 2 sides of brain
Korbinian Brodmann 1909
52 numbered areas of brain
Area 17 Brodmann
Primary visual cortex
Where is area 17?
Back of brain
Area 18
V2
Area 4
Primary motor cortex
Nissl stain
Stains ribosomes which are where cell bodies are so stains cell bodies
Weigert stain
Myelinated axons
Golgi Stain
1)Stains entire neuron
Cell body, neuron and dendrites
2)Only stains small fraction of neurons (seems random)
very useful
Layer 1
Molecular layer
Not many cell bodies, mostly dendrites and synapses
Layer 2
External granule layer
Granule cells (little cells)
Layer 3
External Pyramidal layer
Pyramidal cells (main cells found in cerebral cortex)
Cell body is shaped like a pyramid
Small cells
Layer 4
Internal granule layer
Layer 5
Internal pyramidal layer
BIG PYRAMIDAL CELLS
Biggest neurons found in brain are in Layer 5
Layer 6
Multiform layer
Transitions to white matter
Layer 4 function
Main recipient of afferent inputs from thalamus
Pyramidal neurons in layer 2 and 3
Feedforward projections to other regions of cortex
Large pyramidal neurons in layer V
Project to the basal ganglia, thalamus, brainstem and spinal cord
Driver neurons
Layer VI function
Feedback projections to the thalamus (bursting and tonic mode)
Modulator neurons
Does the thickness of cortex layers vary in diff cortex regions?
YES
Primary Sensory regions of CC layers tend to look like…
Large layer 4 and smaller layers 3 and 5
Primary Motor regions of CC layers tend to look like…
Very little layer 4 and very alrge pyramidal layers like layer 3
What is a cortical column?
The fundamental functional module of the cortex
The neurons in a column are highly interconnected and show similar response properties
Cortex is organized into vertical columns, 100-500 micrometers in diameter
Cortex stuff on the picture
Look at pic
Posterior to central sulcus where postcentral gyrus is is where…
Primary somatic sensory cortex
Somatotopic organization
Where do neurons from SI project?
Somatic sensory association cortex
Somatic sensory association cortex
Parts:
Area 5
SII
Feedforward projections from VI(SI) to V2(S2)
Originate in superficial layers (2,3) and project to layer IV
Feedback projections
Originate in deep layers (5,6) and avoid layer 4 and go to layers (2,3) or (5,6)
Projection of neurons within A COLUMN
Neurons in layer 4 project to layer 2 and 3
Layers 2 and 3 in turn project to layers 5 and 6 and to other cortical areas
Difference between communication/connection of regions vs columns
Central sulcus, followed by postcentral gyrus followed by postcentral sulcus
Receptive fields in somatic sensory ASSOCIATION cortex…
Are larger than in primary somatic sensory cortex bc brain wants to get the big picture
Where pathway
Dorsal, from V1
Sensory information to be used to direct action
What pathway
Ventral, from V1
Object recognition and memory
Main interaction of Pulvinar - Back of thalamus
Posterior Multimodal association cortex
Main interaction of Medial Dorsal Nucleus
Frontal Association cortex
