1.History of Neuroscience and Org. of the Brain

7/31/2019 1.History of Neuroscience and Org. of the Brain

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THEUNI

VERSIT

YOF

CALIFORNIA

BERKELEY

1868

LETTHEREBE

LIGHT

Molecular & Cell Biology

Mammalian Neuroanatomy Fall, 2012

David Larue

MCB 163

Henk Roelink


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PersonnelInstructors:

DavidLarue,LecturerinNeurobiologyOfficehours:Friday;2:004:00pmorbyappointment398LSA

HenkRoelink,Assoc.ProfessorofGenecs,GenomicsandDevelopment Officehours:Friday; 1:00 3:00 pm or by appointment

21KoshlandHall GSIs:

Timothy Day Flannery and Schaffer labs (HWNI) Tuesdaylabs(secons1and2)

Officehours4:30-5:30pmTuesday(aWerlab) room4048VLSB

Caleb Smith Kramer Lab (MCB-Neuro) Thursdaylabs(secons3and4)

Officehours4:30-5:30pmThursday(aWerlab) room4048VLSB


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Academicbackgroundandinterests

DavidLarueundergraduate:UCSantaCruz:BiologyandPsychology,1975 graduate:UCSanFrancisco:Anatomy,1981

researchinterest:anatomyandneurochemistryofthe

centralauditorypathways

HenkRoelinkgraduate:UniversityofAmsterdamandStanfordUniversityresearchinterest:molecularnatureofsignalingmoleculesguidingtheinduconofdisnctneuronpopulaonsinthedevelopingCNS

TimothyDayundergraduate:UniversityofKansas

researchinterest:improvedviralvectorsfortransgenictherapies

forrenaldegeneraon

CalebSmithundergraduate:GrinnellCollege

researchinterest:useoflightmodulatedGABAreceptorsinthe

studyofdendricintegraonandsynapcplascity


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Lecture 1:

History of Neuroscience and the

Organization of the Nervous System

Neuroanatomy takes brains!


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TheOriginsofNeuroscience

Prehistoricancestorsclearlyunderstoodthatthebrainwasvitaltolife Skullsurgeries

Evidence:Trepanaoninbotholdandnewworldcultures,EgypanandIncamummies.

Skullsshowsignsofhealing

AncientGreece Correlaonbetweenstructureandfuncon Hippocrates

Brain:Involvedinsensaon;seatofintelligence


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TheRomanEmpireClaudiusGalen,aGreek,wholivedinthe2ndcentury

intheRomaneraisconsideredtobethefatherofmodernmedicine.ThegreatveinofGaleninthe

brainbearshisname.Hepioneeredhygieneandinsisted

onwelllitandvenlatedroomsforhealing.Galeneven

performedcataractsurgeriesafeatnotmatchedfor

nearlytwomillennia!

Galenthoughtthebrains

ventriclespumpedfluid

throughthenervestoeffect

musclemovementlikea

hydraulicsystemcalledthe

Fluid-Mechanicaltheoryof

brainfuncon,anoonthat

enduredforalmost1500years



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DaVinci[14521519]Hisaccomplishmentscannotbeoverstatedandanatomywasoneofhispassions.Herehe

depictshisinterpretaonofGalensviewoftheventricles

centralroleinmovementandevenvision.

AndreasVesalius[15141564]wasananatomist,physician,andauthorofoneofthemostinfluenalbooksonhuman

anatomy,Dehumanicorporisfabrica(Ontheorkingsofthe

HumanBody).VesaliusisoWenreferredtoasthefounderof

modernhumananatomy.BornAndreasvanesel,likeallacademicsoftheday,heLa


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TheRenaissance:Thebrainasamachine

TheFrenchmathemacian/philosopher,ReneDescartes[1596-1650]wasaproponentofGalensFluid-Mechanical

theoryThehollowventriclesofthe

brainseemedtoharmonizewiththose

oftheheart. Hethoughtthiswouldonlyexplainthe

moremechanicalbehaviorofanimals

Hedrewaclearlinebetweenhumanandanimalthathasinfluencednatural

philosophyeversince Hebelievedthepinealglandwasthe

seatofthesoul(seeaboveright),his

schemeofvisioninvolvedthe

projeconofimageswithinthe

ventriclesontothepinealgland


The Eighteenth CenturyGray matter and white matter distinctions

observed. Gyri, sulci, and fissures andmodern observations of brain injury led to

hypotheses of function

1791 Luigi Galvani [1737-1798]

discovered muscular twitch associatedwith electrical current: "On the Effect of

Electricity on Muscular Motion


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TheOriginsofNeuroscience TheNineteenthCentury:Modernity

1808FranzGallphrenology

1811-CharlesBelltracedthecourseofspinal

nervesanddisnguisheddorsalfromventralroots

1817-JamesParkinsonpublishedthefirst

descriponofshakingsyndromethatnowbearshis

name

1821-FrancoisMagendierepeatsBellsstudyand

showssensoryandmotorfunconofdorsaland

ventralroots(knownastheBell-Magendielaw)

1821-Belldescribesfacialparalysis(Bellspalsy)

1825LuigiRolandodescribedthecentralsulcus

andsubstanagelanosaofthespinalcordboth

ofwhichbearhiseponym


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TheOriginsofNeuroscienceTheNineteenthCentury(cont.)

1837-JanPurkyne(Purkinje)describes

largeoutputcellsofthecerebellum

1838-TheodorSchwanndescribesmyelin

creaonintheperipheralnerves,

proposedhiscelltheorytwoyearslater

1848-PhineasGagesheadisimpaledby

atampingrodinarailroadconstrucon

accidentlobotomy

1849HermannvonHelmholtzmeasures

speedofimpulsesinfrogsciacnerve

1859-RudolphVirchowcoinstheterm

neuroglia1861-PaulBrocaspeechmotor

funcon

1872-GeorgeHunngtondescribesa

hereditarymotorafflicon

1873-CamilloGolgipublisheshissilver

nitratestainforneurons

1884-FranzNissldescribesthegranular

endoplasmicreculum("Nisslbodies")

1884-GeorgesGillesdelaTouree

describesseveralmovementdisorders

1885-Carleigertintroducesmyelin

stainusinghemotoxylin

1889RamonyCajalpresentsneuron

doctrine

1889-CarloMarnodescribescorcal

neuronwithascendingaxon

1897-CharlesSherringtoncoinsterm:

"synapse

1898BayerDrugCo.marketsheroinas

non-addicvemorphinesubstute


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TheOriginsofNeurosciencePhrenology

Phrenology is the study of the structure of the skull todetermine a person's character and mental capacity.

The Viennese physician Franz-Joseph Gall,(1758-1828) claimed there are some 26 "organs" on

the surface of the brain which affect the contour of the

skull, including a "murder organ present in killers.

In1809Gallbeganwringhisgreatestwork:"TheAnatomyandPhysiologyoftheNervousSysteminGeneral,andoftheBraininPar


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Phrenologicalmaps


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Brocaandthelocalizaonoffuncon

LocalizaonofFunconintheBrain

PaulBroca,18241880,FrenchPhysicianandanatomist.

Studyingaphasias,(theinabilitytospeakcoherently),he

discoveredadiscreteregionofthehumancerebrumfor

speech.HismostfamouspaentwasnamedLeborgne,

nicknamed"Tan"duetohisinabilitytoclearlyspeakany

wordsotherthan"tan.Postmortemstudyshowedalesionfromterarysyphilisintheventroposteriorfrontal

lobe.ThisareahasbecomeknownasBrocasarea.


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NeuroscienceToday

Systems:sensoryormotor,anatomyandphysiology Cellular:anatomyandphysiologyofneuronsandgliasynapc

formaonplascityandstudyofneuralcircuitry

Neurochemistry:thediversityofneurotransmiersandreceptorsformthefoundaonformodernneuropharmacology

Behavioral:psychology,ethology Comparaveneuroanatomy:focusontherelaonshipbetween

behavioralspecializaon,anatomicalstructureandevoluonof

phenotype

Cognive:integrave,muldisciplinarystudyofhigherfuncons(fMRI,etc.)usinghumansubjects

Computaonal:studyofbrainfunconintermsoftheinformaonprocessingproperesofthenervoussystem

Moleculardevelopment:neurogenomics,homeoboxgenes,DNAmicroarrays


15/52Copyright2008PearsonEducaon,Inc.,publishingasBenjaminCummings

BasicDivisionsoftheNervousSystem


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TypesofSensoryandMotorInformaon

Copyright2008PearsonEducaon,Inc.,publishingasBenjaminCummings


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Orientaonvectors

Most vertebrates are quadripedswith their neuraxis roughly

parallel to the ground.

Bipedal primates (like us) walkwith the spinal neuraxis

perpendicular to the ground.

This can lead to some confusion

in the orientation vectorterminology.

Rostral means toward the beak

Caudal means toward the tail


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Orientaonvectors

Thus,inarat,thetermsrostral,caudal,dorsal

andventralare

consistentthroughthe

enreneuraxis.

Inhumans,dorsalandventralinthebrainbecomerostraland

caudalinthespinalcord.

inotherwords,wegenerallytreatthehumanbrainandspinal

cordseparatelywith

respecttodireconal

vectors


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Orientaonanddireconaltermsinanatomy

O i t d Di


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OrientaonandDireconsynonyms

Rattus norvegicus

l f f h b


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Planesofreferenceinthebrain

Horizontal Coronal ortransverse Sagittal/mid-sagittal

Because of the cephalic flexure in primates, the spinal axis is roughly

perpendicular to the cerebral axis. Thus, a plane that is horizontalin the brain,

is transverse or coronalin the spinal cord and the trunk. A transverse plane

through the brain, becomes a longitudinal coronalsection through the body

and spinal cord, while sagittalplanes are the same at every level.

Are you confused yet?

Th S i l C d (CNS) d S i l N (PNS)


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TheSpinalCord(CNS)andSpinalNerves(PNS)

Cervical enlargement

Lumbar enlargement

O i f S i l G d hi M


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Gray Matter - dominated by neuronal cell bodies and neuroglia cells H or butterfly shaped

Horns - anterior (ventral), lateral, posterior (dorsal) (sensory &

motor nuclei)

Gray commissure - axons crossing from one side to other Central canal - (continuous with the ventricles of the brain).

White Matter - large numbers of myelinated and unmyelinated axons

Arranged in columns of ascending and descending axons.

contain tracts: sensory or motor; axons in same direction

OrganizaonofSpinalGrayandhiteMaer

D l t l h


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Dorsal-ventralhorns

D l t l h


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Dorsal

Ventral

Graymaer

hitemaer

CentralcanalTracts(columnar)

nuclei

horns

Dorsal-ventralhorns

Dorsalroot

ganglion

B i hi hl i li d


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Brainsarehighlyspecializedto scale

the form of a mammals brainderives from many factors:

body size determines the

overall size and complexity ofcortical folding

relative size of certain regions

of brain reflect behavioraldependence on a particular

sensory modality or motorbehavior hypertrophy of the

auditory midbrain in echolocatingbats is one example

note the enormous cerebellumof the dolphin their brain size is

impressive but so it their overallmass: 330-1435 lbs!


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MajorSubdivisionsoftheBrain

Telencephalon-Cerebrum,Basalganglia

Diencephalon-Thalamus,hypothalamus

Mesencephalon-Midbrain-tectum

Metencephalon-Pons,cerebellum

Myeloencephalon-Medullaoblongata

thalamus means room, or chamber

tectum means roof

pons means bridge

medulla means core

l f h b


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Lateralaspectofthebrain

l d l l l


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Bloodsupply-lateralaspect

middle cerebral artery isthe largest branch of the

internal carotid and the

site of most strokes


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Dorsalandventralaspectsofthebrain

central sulcus

pons

Bl d l t l t


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Bloodsupply-ventralaspect

The circle of Willis, a crucialarterial anastomosis (joining of twoindependent blood supplies) between the

internal carotid and the basilar/vertebralarteries, is a clinical hotspot in neurology.

As many as 80% of arterial aneurysmsoccur here. It is often diagnosed becauseof visual disturbances resulting from

pressure on the optic chiasm/nerves.

Tumors or cysts on the pituitary gland cancreate similar visual signs that lead to anearly diagnosis.

M di l


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Medialaspect

corpus callosum


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Bloodsupply-medialaspect

Venous drainage


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Venousdrainage

(of Galen)

Brain Stem common core of vertebrate brains


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Copyright2003PearsonEducaon,Inc.publishingasBenjaminCummings

BrainStem:commoncoreofvertebratebrains

Some include the diencephalon

B i t d l i


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Brainstemdorsalview

Diencephalon


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Figure 7.15

Epithalamus*

Hypothalamus

Thalamus

Diencephalon

Homeostatic regulation

Sensory relay -target of descending

cortical feedback* epithalamus includes thepineal gland, stria medullaris

and the habenula

Surface features of the human cortex


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Surfacefeaturesofthehumancortex

Corcal areas I


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CorcalareasI

Sensory and motor processing and higher cognitive functions

Corcal areas II


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CorcalareasII

Somatosensory and motor maps - (the homunculus)


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Somatosensoryandmotormaps (thehomunculus)

Deep cerebrum: the basal ganglia (nuclei)


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Deepcerebrum:thebasalganglia(nuclei)Pre-motor planning and coordination: inhibition of unintentional movements

Basal ganglia (nuclei) in horizontal secon


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Basalganglia(nuclei)inhorizontalsecon

Basal ganglia are involved in several movementdisorders, including Parkinsons disease, Huntingtons

Chorea, tic disorders like Tourettes Syndrome andeven obsessive-compulsive disorder (OCD)

M t l i i t i t ti iti hi h f tiCerebellum


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Motor learning, sensorimotor integration, cognitive higher functionsCerebellum

The cranial meninges


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3 connective tissue layers (one menix two or more meninges)

Continuous with the spinal meninges

FUNCTIONS:

1. Cover & protect the CNS2. Protect blood vessels and form sinuses3. Contain CSF4. Form partitions within the skull

Thecranialmeninges

Meningeal layers


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1. DURA MATER (tough or hard mother)

Forms flat partitions provides stabilization and support for the brain and

limits excessive movement

Falx cerebri attaches to the crista galli (cocks comb) of the ethmoid bonein the anterior cranial vault.

Tentorium cerebelli separates the cerebrum from the cerebellum

Subdural space

2. ARACHNOID (spiderweb-like)

Unlike the dura and pia mater, the arachnoid is not always observed as a

discrete membrane but rather as the inner lining of the dura. It does not

extend down into the sulci. The space beneath it is filled with CSF and

criss-crossed with a lacy matrix of fine fibers that led to its name.

Subarachnoid space

3. PIA MATER (soft mother)

Delicate, highly vascular membrane clings tightly to brain over every sulcus

and gyrus

Meningeallayers

Meningeal architecture


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Meningealarchitecture

Cerebrospinal Fluid & the Ventricles


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CerebrospinalFluid&theVentricles

the choroid plexus creates CSF in the ventricles the arachnoid villi reabsorb it

Cerebrospinal Fluid & the Ventricles


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CerebrospinalFluid&theVentricles

Choroid plexus

(one in each ventricle)

arachnoid villus (granulation)

capillaries ependymal cells

Ventricles of the brain


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Contain CSF, a cell-free ultrafiltrate of blood formed by the

CHOROID PLEXUSES there are 4 one in each ventricle

Continuous with each other

1st and 2nd are the lateralventricles in the cerebral

hemispheres

3rd in diencephalon

4th between pons& medulla oblongata(continuous with thecentral canal of thespinal cord)

Ventriclesofthebrain

Circulaon of cerebrospinal fluid (CSF)


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CSFAbsorponofCSF

returns

tovenousblood

Circulaonofcerebrospinalfluid(CSF)

CIRCULATION OF CSF

Replaced every 8 hours


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enoughfordayone

1.History of Neuroscience and Org. of the Brain

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