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Brain - Coggle Diagram
Brain
Functional regionalization
Parietal cortex
Integrate sensory information
Occipital lobe
Visual cortex
Frontal lobe
Judgment and integration
Temporal lobe
memory
Learning
Language processing
Motor cortex
Movement control
Neuron
Def.
Voltage-gated ion channel for action potential
Synaptic transmission
Golgi stain (silver stain)
Axon = uniform diameter
dendritic spine
Polarity
Cell
Pyramidal cell
Prominent nucleolus
Nissl substance (RER)
E.g.
Purkinje cell @ cerebellum
Glia
Glia：Neuron = 1：1
Astrocyte
STAIN
GFAP (glial fibrillary acidic protein) immune-stain
GFAP expression
Neural stem cell
Only at hippocampus or
lateral ventricle in adult
Astrocyte
15% stained
LCK-GFP stain
astrocyte membrane protein
HE stain
the area it controls
astrocytic domain/ synaptic island
Those units it controls
Neuron ensemble
Mechanism
pre-synapse fires
stimulate post-synapse and it release eCB
Endocannabinoids
eCB -> astrocyte and it stimulate other Neuron ensemble
Heterosynaptic potentiation
Negative feedback -> pre-synapse
Homosynaptic
DSE (depolarization-induced suppression of excitation)
Shh(Sonic hedgehog)
Purkinje cell (higher release)
Bergmann glia from astrocyte
granule cell (lower release)
Velate astrocyte
Oligodendrocyte
Function
myelin sheath made
Local trophic effect
STAIN
FISH
HE STAIN
LFB ( Luxol Fast Blue-Cresyl Echt Violet stain)
myelin sheath
Microglia
Function
macrophage @ CNS
silent but low activation threshold
from progenitor cells of yolk sac
STAIN
CD11b
CNS malformations
Neural Tube Defect(NTD)
Neural Tube Closure Defect
1/1000
Classification
Anencephaly
Forebrain closure defect
Area cerebrovasculosa
mainly glia with neuroblasts or neurons
AFP increases
Occipital Encephalocele
Hindbrain neuropore closure defect
occipital lobe herniate through occipital bone / foramen magnum
Pathology
Malformed polymicrogyric cortex
Myelomeningocele
tail bud/lumbar region NTD
both meninges and spinal cord herniate through a large
vertebrate defect
Risk of infection
Spina bifida occulta
asymptomatic
Terminal NTD
Disorder of Forebrain Induction
Holoprosencephaly (HPE)
Prosencephalon abnormal outgrowth and cleavage
Hemispheric cleavage failure
L R brain not divided
1/16000
Cause
Most cases are sporadic
Chromosomal abnormalities
trisomy 13 &18
Genetic defect
Dorsoventral gradient
ZIC2, GLI2
Ventrodorsal gradient
SHH, SIX3, TGI
Environmental factors
Maternal diabetes
Pathology
Prechordal plate(PrCP) secrets Sonic hedgehog(SHH)
facial midline / eye / nose growth
ZIC2 -> telencephalon divided
SHH/ ZIC2 imporant
two eye fields
Type
Lobar holoprosencephaly
mild
Alobar holoprosencephaly
single ventricle
arch- like Hippocampus
midline fusion
thalamus
basal ganglion
STAIN
CTIP2
paucicellular foci
Agenesis of the Corpus Callosum
Corpus callosum complete absent / aplasia or partial absent / hypoplasia
cerature
Radiate pattern of gyri and sulcu
Bat's wing & dilated occipital horn
coincidence lipoma
Neuronal Migration Defect
Cause
gene defect
Lissencephaly
creature
Smaller and lighter
gray heterotopias
Gray matter increases / white matter decreases
4-layered cortex
Smooth lobes with shallow sulci
Cause
arrested neuroblast migration
Gene
Classical lissencephaly
LIS1
X-linked lissencephaly
Doublecortin(DCX)
Neuronal heterotopia
Cause
Defects in neuron migration initiation
Neuroblast stayed in white matter / ventricle
Mutation in cytoskeleton associated protein
loss of function
GENE
ARFGEF mutation
X-linked Dominant
1 more item...
Subtype
nodular
band (regional involvement)
Diffuse (all brain involved)
Polymicrogyria
Casuse
too many or too few gyrus
Gene
NF1 gene mutation
Fukutin
Creature
sometime 6-layered
can be local
Cellular Response to Injury
Reactions of neurons to injury
Death
Red neruron
acute response (12-24hr)
common in hypoxia / ischemia
Eosinophilia
Shrinkage
Pyknosis
Micro
Nissl substance disappear
Regeneration
axonal reaction (central chromatolysis)
enlarged nucleolus
Enlargement & rounding of cell body
Peripheral displacement of nucleus
Dispersion of Nissl substance
Inclusion
Lipofuscin
lipid accumulated
ageing related
Viral inclusion body
Cowdry body(HSV infection)
Negri body(Rabies)
CMV inclusion(CMV)
Reactions of astrocyte to injury
Gliosis
Astrocyte proliferation
Gemistocytic astrocyte
eccentric nucleus
bright-pink cytoplasm
Formation of cytoplasmic inclusion bodies
Rosenthal fibers
αβ-crystallin / hsp27
Corpora amylacea
PAS+
Reactions of Microglia to Injury
Neuronophagia
dying neuron surrounded by activated microglia
microglial nodule
Rod cells
Gitter cells
macrophage w/ lipid
Reactions of Ependymal Cells to Injury
Ependymal granulation
Proliferation of subependymal astrocytes
Loss of ependymal cells