CerebralCortexCerebralCortex. The layer of gray matter covering the entire surface of cerebral...
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Transcript of CerebralCortexCerebralCortex. The layer of gray matter covering the entire surface of cerebral...
The layer of gray matter covering The layer of gray matter covering
the entire surface of cerebral hemispherethe entire surface of cerebral hemisphere
Migration of neurons from inner mantle layer ofMigration of neurons from inner mantle layer of
neural tubeneural tube
Accommodates enormous number of neuronsAccommodates enormous number of neurons
- - Large surface areaLarge surface area accommodates accommodates
more neurons than deep nucleimore neurons than deep nuclei
- - Gyri and sulciGyri and sulci also increase surface area also increase surface area
- - Laminar organizationLaminar organization also accommodates also accommodates
enormous number of neuronsenormous number of neurons
Cerebral CortexCerebral CortexCerebral CortexCerebral Cortex
Numerical DataNumerical Data
Total surface areaTotal surface area: 2200 cm: 2200 cm22 (2.5 ft (2.5 ft22))
about 1/3 ------ surface areaabout 1/3 ------ surface area about 2/3 ------ hidden in the sulciabout 2/3 ------ hidden in the sulci
ThicknessThickness: 1.5 mm (V I) - 4.5 mm (M I): 1.5 mm (V I) - 4.5 mm (M I)
Generally, thickest over the crest of the convolutionGenerally, thickest over the crest of the convolution and, thinnest in the depth of sulciand, thinnest in the depth of sulci
WeightWeight: 600 gm (40 % of total brain weight): 600 gm (40 % of total brain weight)
180 gm --------- neurons180 gm --------- neurons 420 gm --------- glial cells420 gm --------- glial cells
CerebralCerebral CortexCortexCerebralCerebral CortexCortex
Numerical DataNumerical Data
Number of neuronal cells in cerebral cortexNumber of neuronal cells in cerebral cortex
neurons ----------- neurons ----------- 10-15 billion10-15 billion
glial cells ----------glial cells ---------- 50 billion50 billion
Estimation of number of cortical neuronsEstimation of number of cortical neurons
von Economo and Koskinas (1925) von Economo and Koskinas (1925) 14.0 billion 14.0 billion
Shariff (1953)Shariff (1953) 6.9 billion 6.9 billion
Sholl (1956)Sholl (1956) 5.0 billion 5.0 billion
Pakkenberg (1966)Pakkenberg (1966) 2.6 billion 2.6 billion
CerebralCerebral CortexCortex
Subdivision of Cerebral CortexSubdivision of Cerebral Cortex
AllocortexAllocortex
Archicortex (Archipallium)Archicortex (Archipallium)
Palaeocortex (Paleopallium)Palaeocortex (Paleopallium)
IsocortexIsocortex
Neocortex (Neopallium)Neocortex (Neopallium)
cf. mesocortex, juxtallocortex, mesallocortexcf. mesocortex, juxtallocortex, mesallocortex
IsocortexIsocortex – – typicaltypical 6 6 layered cortexlayered cortex
I. I. Molecular LayerMolecular Layer
II. II. External Granular LayerExternal Granular Layer
III.III. External Pyramidal LayerExternal Pyramidal Layer
IV.IV. Internal Granular LayerInternal Granular Layer
V. V. Internal Pyramidal LayerInternal Pyramidal Layer
VI. Polymorphic LayerVI. Polymorphic Layer
Histological OrganizationHistological Organization
Cellular ElementsCellular Elements
1. 1. Pyramidal CellPyramidal Cell - - output neuronoutput neuron
giant pyramidal cell of Betzgiant pyramidal cell of Betz
2. Fusiform Cell ---2. Fusiform Cell --- modified pyramidal cellmodified pyramidal cell
3. 3. Granular (Stellate) CellGranular (Stellate) Cell
basket cell, double bouquet cell, bipolar cell,basket cell, double bouquet cell, bipolar cell,
chandlier cell, neurogliform cellchandlier cell, neurogliform cell
4. Horizontal Cell of Cajal (Retzius-Cajal cell)4. Horizontal Cell of Cajal (Retzius-Cajal cell)
5. Cells of Martinotti5. Cells of Martinotti
CerebralCerebral CortexCortex
1. Pyramidal Cell1. Pyramidal Cell
2. Fusiform Cell 2. Fusiform Cell
3. Granular (Stellate) Cell3. Granular (Stellate) Cell
4. basket cell4. basket cell
5. double bouquet cell 5. double bouquet cell
6. chandlier cell 6. chandlier cell
7. neurogliform cell7. neurogliform cell
8. Horizontal Cell of Cajal 8. Horizontal Cell of Cajal
9. Cells of Martinotti9. Cells of Martinotti
a: axona: axon
CerebralCerebral CortexCortex
I. I. Molecular LayerMolecular Layer
II. II. External Granular LayerExternal Granular Layer
III.III. External Pyramidal LayerExternal Pyramidal Layer
Line of Kaes-BechterewLine of Kaes-Bechterew
IV.IV. Internal Granular LayerInternal Granular Layer
Outer band of BaillargerOuter band of Baillarger
- Line of Gennari- Line of Gennari in area 17 in area 17
V. V. Internal Pyramidal LayerInternal Pyramidal Layer
Giant pyramidal cell of BetzGiant pyramidal cell of Betz
Inner Band of BaillargerInner Band of Baillarger
VI. VI. Polymorphic LayerPolymorphic LayerGolgi Golgi NisslNissl WeigertWeigert
1. corticocortical fiber1. corticocortical fiber association fiber association fiber
commissural fibercommissural fiber 2. thalamocortical fiber2. thalamocortical fiber - specific and non-specific- specific and non-specific
3. extrathalamic subcortical fiber3. extrathalamic subcortical fibercholinergic fiber - acetylcholinecholinergic fiber - acetylcholine basal nucleus of Meynertbasal nucleus of Meynert
mesolimbic dopaminergic fiber - dopaminemesolimbic dopaminergic fiber - dopamine ventral tegmental areaventral tegmental area serotonergic fiber – serotonine - raphe nuclei serotonergic fiber – serotonine - raphe nuclei norepinephrinergic fiber - norepinephrinenorepinephrinergic fiber - norepinephrine nucleus locus ceruleusnucleus locus ceruleus
Cortical Afferent FiberCortical Afferent FiberCortical Afferent FiberCortical Afferent Fiber
Cortical Afferent FiberCortical Afferent FiberCortical Afferent FiberCortical Afferent Fiber
1. association fiber 1. association fiber
2. commissural fiber2. commissural fiber
3. specific3. specific thalamocortical fiberthalamocortical fiber
4. non-specific4. non-specific thalamocortical fiberthalamocortical fiber
1. Corticofugal Fiber - Projection Fiber1. Corticofugal Fiber - Projection Fiber
corticostriate fibercorticostriate fiber corticothalamic fibercorticothalamic fiber corticorubral fiber corticorubral fiber corticotectal fiber corticotectal fiber corticopontine fiber corticopontine fiber cortico-olivary fiber cortico-olivary fiber corticobulbar fibercorticobulbar fiber corticospinal fibercorticospinal fiber
2. Corticocortical Fiber2. Corticocortical Fiber Association fiberAssociation fiberCommissural fiberCommissural fiber
Cortical Efferent FiberCortical Efferent FiberCortical Efferent FiberCortical Efferent Fiber
5. 5. association fiberassociation fiber
6. 6. commissural fibercommissural fiber
7. 7. corticostriate fibercorticostriate fiber
8. 8. corticorubral fiber corticorubral fiber
corticopontine fiber corticopontine fiber
corticobulbar fibercorticobulbar fiber
9. 9. corticospinal fibercorticospinal fiber
corticotectal fibercorticotectal fiber
10. 10. corticothalamic fiber corticothalamic fiber
Cortical Efferent FiberCortical Efferent FiberCortical Efferent FiberCortical Efferent Fiber
A. A. pyramidal neuronpyramidal neuron
B. excitatoryB. excitatorygranular cellgranular cell
C.C. inhibitoryinhibitorygranular cellgranular cell
1. 1. afferentafferent fiber fiber
2.2. efferent fiberefferent fiber
3.3. corticothalamic fibercorticothalamic fiber
Columnar Cortical Unit and Cortical CircuitaryColumnar Cortical Unit and Cortical CircuitaryColumnar Cortical Unit and Cortical CircuitaryColumnar Cortical Unit and Cortical Circuitary
A. A. Homotypical isocortexHomotypical isocortex
-------------- association cortexassociation cortex
B. Heterotypical isocortexB. Heterotypical isocortex
1. granular cortex 1. granular cortex
------ primary sensory cortexprimary sensory cortex
V I (17), S I (3), A I (41) V I (17), S I (3), A I (41)
2. agranular cortex2. agranular cortex
------ motor cortexmotor cortex
M I (4), PM (6)M I (4), PM (6)
Regional Variation of Cortical LaminationRegional Variation of Cortical LaminationRegional Variation of Cortical LaminationRegional Variation of Cortical Lamination
Phrenology of Gall and SpurzheimPhrenology of Gall and Spurzheim
Clinical evidencesClinical evidences
Broca’s area (1861)Broca’s area (1861)
Jacksonian epilepsy (1864)Jacksonian epilepsy (1864)
Experimental evidencesExperimental evidences
Fritsch and Hitzig (1870) --- motor cortexFritsch and Hitzig (1870) --- motor cortex
von Gudden (1870) ---- visual cortexvon Gudden (1870) ---- visual cortex
Ferrier (1873) ---- auditory cortexFerrier (1873) ---- auditory cortex
Functional Localization of Cerebral CortexFunctional Localization of Cerebral CortexFunctional Localization of Cerebral CortexFunctional Localization of Cerebral Cortex
based on cytoarchitectonic studiesbased on cytoarchitectonic studies
Campbell (1905) -------- Campbell (1905) -------- about 20 areasabout 20 areas
Brodmann (1909) ------Brodmann (1909) ------ 47 areas47 areas
- most popular- most popular
Vogt and Vogt (1919) -Vogt and Vogt (1919) - over 200 areasover 200 areas
von Economo (1929) --von Economo (1929) -- 109 areas109 areas
Morphological Classification of Cortical AreasMorphological Classification of Cortical AreasMorphological Classification of Cortical AreasMorphological Classification of Cortical Areas
Brodmann’s cytoarchitectorial map (Lateral surface)Brodmann’s cytoarchitectorial map (Lateral surface)
Brodmann’s cytoarchitectorial map (Lateral surface)Brodmann’s cytoarchitectorial map (Lateral surface)
Sensory areaSensory area primary sensory areaprimary sensory area secondary sensory areasecondary sensory area
Motor areaMotor area
primary motor areaprimary motor area secondary motor areasecondary motor area supplementary motor areasupplementary motor area
Association areaAssociation area
parietal, occipital and temporal cortexparietal, occipital and temporal cortex - conceptual elaboration of sensory data- conceptual elaboration of sensory data prefrontal (frontal) cortexprefrontal (frontal) cortex - judgement, foresight- judgement, foresight
Functional Localization of Cerebral CortexFunctional Localization of Cerebral CortexFunctional Localization of Cerebral CortexFunctional Localization of Cerebral Cortex
Somesthetic Area (Somesthesia)Somesthetic Area (Somesthesia) S I, S IIS I, S II
Visual Area (vision)Visual Area (vision) V I, V IIV I, V II
Auditory Area (Hearing)Auditory Area (Hearing) A I, A IIA I, A II
Vestibular Area (Equilibrium)Vestibular Area (Equilibrium)
Gustatory Area (Taste)Gustatory Area (Taste)
Olfactory Area (Smell)Olfactory Area (Smell)
Sensory AreasSensory AreasSensory AreasSensory Areas
S I S I ----- 3, 1, 2 (postcentral gyrus)----- 3, 1, 2 (postcentral gyrus)
afferernts: ventrobasal complex (VPLc, VPM)afferernts: ventrobasal complex (VPLc, VPM)
discrimination of position and intensity of sensationdiscrimination of position and intensity of sensation
S II S II ---- superior bank of lateral fissure---- superior bank of lateral fissure
no clinical disordersno clinical disorders
Somesthetic Association CortexSomesthetic Association Cortex
------- 5, 7 (parietal lobule, precuneus)------- 5, 7 (parietal lobule, precuneus)
afferents: S I, LP of thalamusafferents: S I, LP of thalamus
integration of geneal sensation with past experienceintegration of geneal sensation with past experience
tactile agnosia, astereognosistactile agnosia, astereognosis
Somesthetic AreaSomesthetic AreaSomesthetic AreaSomesthetic Area
SecondarySecondary
Somesthetic Somesthetic
Area (SII)Area (SII)
superior bank of superior bank of
lateral fissurelateral fissure
V I ----- V I ----- 17 (striate cortex - line of Gennari)17 (striate cortex - line of Gennari)
greatly thickened outer band of Baillargergreatly thickened outer band of Baillarger
heterotypical isocortexheterotypical isocortex
afferent: LGd of thalamusafferent: LGd of thalamus
visual field defect:visual field defect:
homonymous quadranopsia and macular sparinghomonymous quadranopsia and macular sparing
V II ---- V II ---- 18, 19 (visual association area)18, 19 (visual association area)
afferents: V I, pulvinar of thalamusafferents: V I, pulvinar of thalamus
integration of vision with past experienceintegration of vision with past experience
visual agnosiavisual agnosia
cf. occipital eye fieldcf. occipital eye field
Visual CortexVisual CortexVisual CortexVisual Cortex
V4V4(color)(color) FaceFace
recognitionrecognitionPerceivePerceive
Facial ExpressionFacial Expression
VisualVisualassociationassociation
areasareas
A I ----- A I ----- 41, 42 (trannsverse temporal gyrus of Heschl)41, 42 (trannsverse temporal gyrus of Heschl)
heterotypical isocortexheterotypical isocortex
afferents: MGv of thalamus - core projectionafferents: MGv of thalamus - core projection
slight diminution in auditory acuityslight diminution in auditory acuity
A II ---- A II ---- 22 (Wernike's area of original connotaion)22 (Wernike's area of original connotaion)
not well-definednot well-defined
afferents: non-laminar part (MGm, MGd) – belt projectionafferents: non-laminar part (MGm, MGd) – belt projection A IA I
auditory agnosia - sensory aphasiaauditory agnosia - sensory aphasia
Auditory CortexAuditory CortexAuditory CortexAuditory Cortex
Vestibular AreaVestibular Area
Area 3a and 2v of S IArea 3a and 2v of S I
afferents: VPLoafferents: VPLo
[superior temporal gyrus anterior to A I][superior temporal gyrus anterior to A I]
Gustatory AreaGustatory Area
Area 43 (inferior end of postcentral gyrus)Area 43 (inferior end of postcentral gyrus)
afferents: VPMpcafferents: VPMpc
Olfactory AreaOlfactory Area
Piriform Lobe - Limbic SystemPiriform Lobe - Limbic System
Other Primary Sensory AreasOther Primary Sensory AreasOther Primary Sensory AreasOther Primary Sensory Areas
primary Motor Area (M I)primary Motor Area (M I)
Premotor Area (PM) Premotor Area (PM)
Supplementary Motor Area (SMA)Supplementary Motor Area (SMA)
Frontal Eye FieldFrontal Eye Field
Motor AreasMotor AreasMotor AreasMotor Areas
M I ------- 4 M I ------- 4
precentral gyrus of lateral surfaceprecentral gyrus of lateral surface
anterior part of paracentral lobuleanterior part of paracentral lobule
heterotypical agranular cortexheterotypical agranular cortex
giant pyramidal cell of Betzgiant pyramidal cell of Betz
afferents: premotor area, SMA, S Iafferents: premotor area, SMA, S I
VLc, VPLo of thalamusVLc, VPLo of thalamus
Motor HomunculusMotor Homunculus
Upper Motor Neuron (UMN) syndromeUpper Motor Neuron (UMN) syndrome
Primary Motor AreaPrimary Motor Area
Premotor Area (PM) ------Premotor Area (PM) ------ lateral surface of 6lateral surface of 6
afferents: VLc, VPLo of thalamus from cerebellumafferents: VLc, VPLo of thalamus from cerebellum
Supplementary Motor Area (SMA)Supplementary Motor Area (SMA)
---------------------------------------------------- medial surface of 6medial surface of 6
afferents: VLo, Vapc of thalamus from basal gangliaafferents: VLo, Vapc of thalamus from basal ganglia
Frontal Eye Field ----------Frontal Eye Field ---------- 88
voluntary tracking movementvoluntary tracking movement
Other Motor AreasOther Motor Areas
Language Areas ----- 22, 39, 40, 44, 45Language Areas ----- 22, 39, 40, 44, 45
Posterior Parietal Association AreaPosterior Parietal Association Area
------ ------ 5, 75, 7 (39, 40)(39, 40)body imagebody image
Temporal Association Area Temporal Association Area ------ ------ 20, 21, 37, 20, 21, 37, 38 38 (22)(22)
multisensory integration, conceptual ideationmultisensory integration, conceptual ideation
Prefrontal Association AreaPrefrontal Association Area
----- ----- 9, 10, 11, 12, 46, 47 9, 10, 11, 12, 46, 47 (44, 45)(44, 45)
judgement, foresight, personalityjudgement, foresight, personality
Association AreasAssociation Areas
AgnosiaAgnosia
Tactile agnosiaTactile agnosia Visual agnosiaVisual agnosia
AlexiaAlexia Auditory agnosiaAuditory agnosia
ApraxiaApraxia
AphasiaAphasia
Wernicke’s (receptive) aphasiaWernicke’s (receptive) aphasia Broca’s (Motor) aphasiaBroca’s (Motor) aphasia conduction aphasiaconduction aphasia global aphasiaglobal aphasia
Disorders of Association CortexDisorders of Association CortexDisorders of Association CortexDisorders of Association Cortex
ApraxiaApraxiaApraxiaApraxia
The inability to execute a voluntary motor movement despite being The inability to execute a voluntary motor movement despite being able to demonstrate normal muscle function.able to demonstrate normal muscle function.
Sensory Language Area (Wernike's area) ---- Sensory Language Area (Wernike's area) ---- 22, 39, 4022, 39, 40
ReceptiveReceptive AphasiaAphasia - - area 22area 22 defect in comprehension, good spontaneous speechdefect in comprehension, good spontaneous speech AnomicAnomic AphasiaAphasia - - word finding difficultyword finding difficulty JargonJargon aphasiaaphasia - - fluent, but unintelligiable jargon fluent, but unintelligiable jargon
39 (supramarginal gyrus), 40 (angular gyrus)39 (supramarginal gyrus), 40 (angular gyrus)
Superior Longitudinal FasciculusSuperior Longitudinal Fasciculus
ConductionConduction AphasiaAphasia good comprehension, good spontaneous speechgood comprehension, good spontaneous speech poor repetition, poor responsepoor repetition, poor response
Motor Language Area (Broca’s area) --- 44, 45Motor Language Area (Broca’s area) --- 44, 45
MotorMotor ApahsiaApahsia good comprehension, no speechgood comprehension, no speech
Language AreasLanguage Areas
Cerebral Dominance (Lateralization, Asymmetry)Cerebral Dominance (Lateralization, Asymmetry)
Dominant HemisphereDominant Hemisphere
LanguageLanguage
– – speech, writingspeech, writing
CalculationCalculation
Non-dominant HemisphereNon-dominant Hemisphere
Spatial Perception (3D subject)Spatial Perception (3D subject)
SingingSinging
Playing musical instrumentPlaying musical instrument
LanguageLanguage
SpeechSpeech
WritingWriting
CalculationCalculation
3D perception3D perception
SingingSinging
Playing Musical Playing Musical
instrumentinstrument
Roger Sperry Roger Sperry
(1913-1994)(1913-1994)
1981 Nobel 1981 Nobel LaureateLaureate
Split BrainSplit BrainSplit BrainSplit Brain
CommissuratomyCommissuratomy
(split corpus callosum)(split corpus callosum)
Two minds in one brain?Two minds in one brain?
Frontal Granular CortexFrontal Granular Cortex
Lateral Prefrontal Association AreaLateral Prefrontal Association Area
------ ------ 9, 10, 469, 10, 46
judgement, foresight, problem solvingjudgement, foresight, problem solving
Orbitofrontal CortexOrbitofrontal Cortex ------ ------ 11, 12, 47 11, 12, 47
emotion, olfaction, personalityemotion, olfaction, personality
Case of Case of Phineas GagePhineas Gage
Prefrontal Leucotomy of Prefrontal Leucotomy of MonizMoniz and and FreemanFreeman
Prefrontal Association AreasPrefrontal Association Areas
Phineas Gage’s lesion reconstructedPhineas Gage’s lesion reconstructed(H. Damasio and R. Frank, 1992)(H. Damasio and R. Frank, 1992)
Prefrontal LeucotomyPrefrontal Leucotomy(Frontal Lobotomy)(Frontal Lobotomy)
Antonio Egas MonizAntonio Egas Moniz