Exam I Flashcards
Early goal of neuroscience
map the brain by characterizing the effects of damage and disease
Task-based analysis
Can characterize the precise nature of deficits
Limitation: not useful for normal mental activity
Gold standard for understanding critical structures for brain function
Lesioning; causation not correlational
Baddeley & Hitch Model
Phrenology
Gall
by touching skull, you can make assessments on personality
PRESUMPTION –> brain would be bigger/smaller ; (convexities/concavities) depending on the functions you possess
Localization
localization: different aspects of brain function are governed by, and therefore localizable to different centers of the brain
Mass Action
brain function distributed throughout the cortex
Pierre Flourens
critic of phrenology (Gall’s localization)
would lesion animals in localized spots; failed to find evidence of localization (cerebral cortex)
EQUIPOTENTIALITY:
Equipotentiality
Pierre Flourens
any given piece of cortical tissue had potential to support any brain function
overtime, animals with experimental damage recovered without repair to damaged tissue itself, assumed other parts could take over
Evidence for localization
Gall “phrenology”
Paul Broca “tan”
John Hughlings Jackson “jacksonian march”
Evidence for mass action
Pierre Flourens “equipotentiality” animal lesions
Jacksonian March
John Hughlings Jackson
noticed there was a specific sequence of body parts that correlate with seizure activity traveling along motor cortex
Paul Broca
tan
language production
left frontal cortex
Factor that advanced brain studies
aseptic surgery
Method of learning a great deal about neural function
studying morphology from brain tissue under microscope
Camilo Golgi
developed a silver stain that allowed for visualization of individual neurons
BELIEVED brain was a continuous mass of tissue with a common cytoplasm
Synctyium
Santiago Ramon y Cajal
Neural Doctrine: nervous system made up of individual neurons
Neuron Doctrine
Ramon y Cajal
nervous system made up of individual neurons
Fritzch and Hitzig
reported that electrical stimulation in anterior part of dog’s frontal lobe produced movement in opposite side of body
part of body affected varied systematically with positioning of electrode
supported Jackson’s somotropic organization
Describe the process of neuronal communication
electrical-chemical transmission
(1) electrical impulses carry signals along axon
(2) chemical transmitters carry signals between neurons across synapse
Describe neuronal communication
Describe
PSP Summation
postsynaptic potential summation – EPSPs and IPSPs integrate spatially and temporally at the axon hillock
their summation determines signal
IPSP: hyperpolarization, cell further away from threshold, less likely to fire
EPSP: depolarization, generates action potential
Glutamate
EPSP
excitatory neurotransmitter
opening of Na+
GABA
IPSP
inhibitory neurotransmitter
influx of Cl- ions, hyperpolarizing cell /orK+
Acetylcholine
excitatory neurotransmitter
opening of Na+
Acetylcholine: facilitates learning and memory
• affected in Alzheimer’s Disease
Excitatory NTs
glutamate, acetylcholine
Inhibitory NTs
GABA, glycine
Neuromodulators
modulate activity in large regions rather than
strictly exciting/inhibiting specific postsynaptic neurons
dopamine, norepinephrine, serotonin
Neurotransmitters
transmitting signals between neurons
exciting/inhibiting specific postsynaptic neurons
Norepinephrine
Norepinphrine: enhances vigilance & preparation for action
Dopamine
facilitates movement, reinforces behaviors,
helps keep information in short-term (working) memory
• affected in Parkinson’s Disease (low), schizophrenia (high)
Serotonin
inhibits some behaviors; lots of other effects
• affected in Depression
Agonist
fully activates the receptor that it binds to
Antagonist
binds to a receptor but does not activate and can block the activity of other agonists
brain orientations
dorsal: top
ventral: bottom
anterior: front
posterior: back
rostral: front
caudal: back
medial: middle
lateral: side
Electrochemical communication
electrical signal propagated down axon, converted to chemical signal and transmitted across synapse
3 basic neuronal components
soma, dendrites, axon
Evolution of brain morphology
computational power of brain increased over time…more wrinkled and compacted to fit (gyrations)
optimally shaped to minimize connection distance between distant groups of neurons
Gray v. White matter
location in brain
gray matter=border=glial cells (cell bodies)
white matter=majority, middle=axons
Brain slicing
axial: top and bottom
sagittal: side and side
coronal: front and back
gyrus and sulcus
gyrus: top
sulcus: bottom
4 lobes of brain
FPOT
frontal: executive functioning
parietal: perception, making sense of world
occipital: vision
temporal: memory
central sulcus
separates frontal and parietal lobe, deep groove
separates motor and sensory cortex
precentral sulcus
primary motor cortex
postcentral sulcus
somatosensory cortex
sylvian fissure
separates parietal and temporal lobes
insula buried within it
line of Gennari
white
primary visual cortex
Brodmann
cytoarchitectonic
52 layers, based on cell morphology, density, and layering
Cytoarchitect
Brodmann
52 layers, based on cell morphology, density, and layering