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    s

    Il existe unvieux dbat en

    neurosciencessur les

    contributionsrelatives duthalamus et du

    cortex dans leprocessus qui

    produitl activitcrbraleprsente dans

    le cortexsensoriel

    primaire

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    es deux positions dans ce dbat A un extrme se

    trouve un modlede type -feed

    forward o lesconnexionscorticales

    locales ne jouentpas un rle

    dominant etl activit est

    dictemajoritairementpar les entresthalamiques( ).Hubel et Weisel

    A l autre extrmese trouve le

    point de vueselon lequel

    l informationvenant du

    thalamus ne faitque

    perturber l activit spontane dj

    prsente dans unrseau cortical

    fortement.interconnect

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    A Lejeune 3

    Perceptron dpourvu d activitspontane

    Activit spontane dj prsentedans un rseau cortical fortement

    interconnect

    es deux positions dans ce dbat

    Schematic diagram of circuitry for the lateral.geniculate nucleus The inputs to relay cells

    are shown along with the relevantneurotransmitters and postsynaptic receptors

    ( ) :ionotropic and metabotropic AbbreviationsLGN , ;lateral geniculate nucleus BRF , brainstem;reticular formation TRN , thalamic reticular

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    A Lejeune 4

    a position de la poule a position de l oeuf

    tendu l ensemble des sciences( , )ognitives Varela 1992

    Le mondeextrieur

    comporte desrgles fixes; ilprcde limagequil projette sur

    le systmecognitif dont latche est desaisir le monde

    de manireapproprie (que

    Le systmecognitif cre son

    propre monde, ettoute sonapparentesolidit repose

    sur les loisinternes delorganisme

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    Prsentation dun article auprofesseur Thomas Gisiger

    dans le cadre du cours

    Somatosensory CorticothalamicProjections: Distinguishing

    Drivers from Modulators

    par

    Iva Reichova et S. MurraySherman

    Journal of Neurophysiology, 2004

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    A Lejeune 6

    IntroductionRappel: les rcepteurs ioniques et mtabotropiquesRappel: les effets inhibiteur ou exitant

    The ion channel is regulated by a ligand and is usually veryselective to one or more ions likeNa+,K+,Ca +2 , or Cl-. Suchreceptors located at synapses convert the chemical signal of

    presynaptically released neurotransmitter directly and veryquickly into a postsynaptic .electrical signal

    n contrast to the latter ,etabotropic eceptors do notorm an on channelpore ; ,atherhey are indirectly linked with-on channels on the plasmaembrane of the cell throughignal transduction ,mechanismsoften proteins . ,ence they aretype of-protein coupled receptor.

    thers are yrosine kinases orguanylylcyclasereceptors .

    F t t

    http://en.wikipedia.org/w/index.php?title=Guanylyl_cyclase_receptors&action=edit&redlink=1http://en.wikipedia.org/wiki/Ion_channelhttp://en.wikipedia.org/wiki/Ligand_(biochemistry)http://en.wikipedia.org/wiki/Sodiumhttp://en.wikipedia.org/wiki/Potassiumhttp://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Chloridehttp://en.wikipedia.org/wiki/Synapsehttp://en.wikipedia.org/wiki/Presynaptichttp://en.wikipedia.org/wiki/Postsynaptichttp://en.wikipedia.org/wiki/Ion_channelhttp://en.wikipedia.org/wiki/Porehttp://en.wikipedia.org/wiki/Signal_transductionhttp://en.wikipedia.org/wiki/G_proteinhttp://en.wikipedia.org/wiki/G_proteinhttp://en.wikipedia.org/wiki/G_protein-coupled_receptorhttp://en.wikipedia.org/wiki/G_protein-coupled_receptorhttp://en.wikipedia.org/wiki/Receptor_tyrosine_kinasehttp://en.wikipedia.org/w/index.php?title=Guanylyl_cyclase_receptors&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Guanylyl_cyclase_receptors&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Guanylyl_cyclase_receptors&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Guanylyl_cyclase_receptors&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Guanylyl_cyclase_receptors&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Guanylyl_cyclase_receptors&action=edit&redlink=1http://en.wikipedia.org/w/index.php?title=Guanylyl_cyclase_receptors&action=edit&redlink=1http://en.wikipedia.org/wiki/Receptor_tyrosine_kinasehttp://en.wikipedia.org/wiki/Receptor_tyrosine_kinasehttp://en.wikipedia.org/wiki/G_protein-coupled_receptorhttp://en.wikipedia.org/wiki/G_proteinhttp://en.wikipedia.org/wiki/Signal_transductionhttp://en.wikipedia.org/wiki/Porehttp://en.wikipedia.org/wiki/Ion_channelhttp://en.wikipedia.org/wiki/Postsynaptichttp://en.wikipedia.org/wiki/Presynaptichttp://en.wikipedia.org/wiki/Synapsehttp://en.wikipedia.org/wiki/Chloridehttp://en.wikipedia.org/wiki/Chloridehttp://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Calciumhttp://en.wikipedia.org/wiki/Potassiumhttp://en.wikipedia.org/wiki/Potassiumhttp://en.wikipedia.org/wiki/Sodiumhttp://en.wikipedia.org/wiki/Sodiumhttp://en.wikipedia.org/wiki/Ligand_(biochemistry)http://en.wikipedia.org/wiki/Ion_channel
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    ( )A

    ( , )Reichova et Sherman 2004

    L aire corticale 1tant une aire

    ,sensorielle primaire sacouche 4

    est la cible deprojections du noyau

    sensoriel thalamique A(le CGL par ).exemple

    ,Les aires corticales 12 et 3 sont aussi

    relies par desprojections -cortico corticales

    -liant leurs couches 1 3.et 6

    Le noyau thalamique Areoit aussi des

    projections en retour

    de l aire ,corticale 1 qui sont

    issues de sa couche 6

    Firsttransmission to

    cortex from the=periphery DRIVER

    :GN Lateral Geniculate Nucleus:P Ventral Posterior Nucleus

    Firsttransmission to

    cortex from the=periphery DRIV

    ER

    Drivers et ModulatorsF rst transm ss onto cortex from the

    periphery=DRIVER

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    ( )A ( )B

    Les inputscholinergiques

    du niveau 5

    Le noyau B reprsentepar exemple

    une partie du.pulvinar

    l ne reoit aucune nformationsensorielle , mais il est la ciblede connexions projetes

    par les neurones descouches 4 et 5 de

    .l aire corticale 1 Il est aussi connect

    ,avec l aire 2projetant sur sa

    Drivers et Modulators

    DRIVER

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    n veau eslimite lamorphologie(Flowery) Li et al.(2003)

    e but de cetteecherche estapprofondir cette.ypothse de Li et al( ) 003 qui distinguentur des basesorphologiques deuxroupes d inputs sur leateral Posterior( ):halamus LPT- n groupe avec ynaptic depression;nhibiteur- - n groupe avec ynaptic acilitationtimulation sansoutefois identifiera source corticale( )iveau 5 OU 6?

    Drivers et Modulators

    n va donc activer les axones des couches 5 et 6 sur uneouche thalamocorticale et enregistrer les rponses sur le( )oyau ventral postrieur 1er ordre FO et le noyau mdial( )ostrieur HO

    Fi d l h fi i i

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    Design de larecherche

    Retinogeniculate activation evoked large, all-or-none excitatory postsynaptic potentials(EPSPs) that showed paired-pulse depression antagonized by N-methyl-D-aspartate (NMDA)and AMPA receptor blockers butwith no sign of a metabotropic glutamate receptor (mGluR)component.Corticogeniculate activation evoked small, graded EPSPs showing paired-pulsefacilitation, and the EPSPs showed both NMDA and AMPA receptor component plus anmGluR1 component

    n vestig ate syna p tic p rop erties ofo rtico th a la m ic in p u ts8 ce lls

    comparaison avec

    -First order relays represent the first transmissionto cortex of particular type of information from the periph

    -Higher order relays serve to transmit information between- -cortical areas via a cortico thalamo cortical route

    cellsHOst O

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    methods

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    thalamocorticalslice preparationasseen in recordingchamber

    A: lower-power view ofslice. Barrel cortex (BC)can be clearly identifiedaswell as the externaland internal capsules(EC, IC) andthe ventral posterior(medial and lateral) andposteriormedial nuclei(VP,POm). The stimulating

    electrode isshown in the barrelcortex and recordingelectrodes arelocated in the ventralposterior and posterior

    medialnuclei.

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    Recordings from geniculate cells wereperformed under visual control.

    Electrical stimulation was performed inthe

    optic tract, which lies ventral to the

    lateral geniculate nucleus, and in theoptic radiations, which lie dorsal.

    Stimulation andrecording (2)

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    Rappel:A receptorantagonist is

    1] In pharmacology,antagonists have affinitybut no efficacy for their

    cognate receptors, andbinding will disrupt theinteraction and inhibit thefunction of an agonist orinverse agonist at receptors.Antagonists mediate theireffects by binding to theactive site or to allostericsites on receptors, or theymay interact at uniquebinding sites not normallyinvolved in the biological

    '

    A receptorantagonist is atype ofreceptorligand ordrug that doesnot provoke abiologicalresponse itself

    upon binding toa receptor, butblocks ordampens agonist-mediatedresponses.[

    D e s a n ta g o n iste s so n t u tilis s su r le s( ),rcep teu rs G A B A a et b

    , ,A M PA m G lu R m G lu R 5

    http://smb//tmp/sv8h6.tmp/#cite_note-pharmguide-0http://en.wikipedia.org/wiki/Pharmacologyhttp://en.wikipedia.org/wiki/Dissociation_constant%23Protein-Ligand_bindinghttp://en.wikipedia.org/wiki/Efficacy%23Pharmacologyhttp://en.wikipedia.org/wiki/Agonisthttp://en.wikipedia.org/wiki/Inverse_agonisthttp://en.wikipedia.org/wiki/Receptor_(biochemistry)http://en.wikipedia.org/wiki/Ligand_(biochemistry)http://en.wikipedia.org/wiki/Drughttp://en.wikipedia.org/wiki/Receptor_(biochemistry)http://en.wikipedia.org/wiki/Agonisthttp://smb//tmp/sv8h6.tmp/#cite_note-pharmguide-0http://smb//tmp/sv8h6.tmp/#cite_note-pharmguide-0http://en.wikipedia.org/wiki/Agonisthttp://en.wikipedia.org/wiki/Receptor_(biochemistry)http://en.wikipedia.org/wiki/Drughttp://en.wikipedia.org/wiki/Ligand_(biochemistry)http://en.wikipedia.org/wiki/Receptor_(biochemistry)http://en.wikipedia.org/wiki/Inverse_agonisthttp://en.wikipedia.org/wiki/Agonisthttp://en.wikipedia.org/wiki/Efficacy%23Pharmacologyhttp://en.wikipedia.org/wiki/Dissociation_constant%23Protein-Ligand_bindinghttp://en.wikipedia.org/wiki/Pharmacologyhttp://smb//tmp/sv8h6.tmp/#cite_note-pharmguide-0http://smb//tmp/sv8h6.tmp/#cite_note-pharmguide-0
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    A Lejeune 15

    . Antagonist activitymay be reversible orirreversibledepending on thelongevity of the

    antagonistreceptorcomplex, which, inturn, depends on thenature of antagonistreceptor binding.

    The majority of drugantagonists achievetheir potency bycompeting withendogenous ligandsor substrates atstructurally-defined

    A receptorantagonist is(2)

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    A Lejeune 16

    Paired-pulse facilitation:definition

    When a presynaptic neuron receivestwo stimuli in rapid succession, thepostsynaptic response will commonly

    be larger for the second than for thefirst pulse a phenomenon known aspaired-pulse facilitation (PPF). Now

    here's an easy question for everyneurophysiologist: what is themechanism responsible for PPF?Although most people will quicklypoint in the direction of 'residual

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    Paired-pulse depression

    When two depolarizing stimuli aredelivered in close succession to a

    group of axons, their averageresponse to the second one issometimes smaller than to thefirst. This form of short-term

    plasticity is more common atinhibitory than at excitatorysynapses.

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    A Lejeune 18

    resultsEPSPs showing the modulator signature :paired-pulsefacilitation, graded response, mGluR component; the driversignature : paired-pulse depression, all-or none response,no mGluR component

    th l ti l

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    thalamocorticalslice preparationasseen in recordingchamber

    A: lower-power view ofslice. Barrel cortex (BC)can be clearly identifiedaswell as the externaland internal capsules

    (EC, IC) andthe ventral posterior(medial and lateral) andposteriormedial nuclei(VP,POm). The stimulating

    electrode isshown in the barrelcortex and recordingelectrodes arelocated in the ventralposterior and posterior

    medialnuclei.

    To iso la te excita to ry p o stsy n a p tic p o te n tia ls( ) ,EPSPs in allrecordings we used GABA receptor

    a n ta g o n ists

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    A Lejeune 20

    ynap c npu s o ce s othe lateral geniculate

    nucleus

    To h e lp e sta b lish syn a p tic p ro p e rtie s o fd rive rs a n d co n tra st th e m w ith la ye r 6

    ,m o d u la to r p ro p e rtie s w ith o u r te ch n iq u e s w efirst re co rd e d fro m th e la te ra lg e n icu la te

    .n u cle u s

    : ;rat G ran seth an d Lind stro m 20 03 Turne r; :a n d S a lt 1 9 9 8 m o u se C h e n a n d R e g e h r

    ; .2 0 0 0 C h e n e t a l ; :20 02 gu ine a pig; :M cCo rm ick and Von K rosigk 1 99 2 cat

    ;Lind stro m an d W ro be l1 9 9 0 also ou r ow nu n p u b lishe d o b serva tion s

    W e th u s e le ctrica lly stim u la te dth e o p tic tra ct an d ra d ia tio n s w h ile

    re co rd in g fro m.g e n icu la te re la y ce lls

    d d l t i sh o in g e cita to r p o sts n a p tic p o te n tia ls

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    A Lejeune 2 1

    In this and all subsequentfiguresshowing evoked EPSPs,inhibition was blocked byapplication of SR95531 (aGABAA antagonist, 20 M) and

    CGP46381 (a GABABantagonist, 40 M). A, i and ii: large EPSP

    showing paired-pulsedepression evokedfrom retinogeniculate

    stimulation (Ai)contrasts with smallEPSP showing paired-pulse facilitationevoked fromcorticogeniculate

    stimulation (Aii). B i and ii: increasin

    . .and modulators inthe mouse lateralgeniculatenucleus

    sh o w in g excita to ry p o stsyn a p tic p o te n tia ls( )EPSPs evoked from stimulation of

    re tin o g e n icu la te a ffe re n ts via th e o p tic tra ct( )Ai Di or corticogeniculate afferents via

    (the optic radiation )Aii Dii

    d d l t i sh o w in g excita to ry p o stsyn a p tic p o te n tia ls

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    A Lejeune 22

    C, i and ii: EPSPs evokedby low-frequencystimulation (10 Hz) fromboth sites completelyblocked by AMPA and N-methyl-D-aspartate (NMDA)receptor antagonists (DNQX,50 M, and MK-801, 50 M,respectively).

    D, i and ii: high-frequencystimulation (HFS, 110 Hz)of retinogeniculateafferents evokes no

    further response withcontinued application ofAMPA and NMDAantagonists (Di).

    Low-frequency stimulation(LFS, 10 Hz) ofcorticogeniculate afferents in

    the presence of continuedAMPA and NMDA antagonists

    . .and modulators inthe mouse lateralgeniculatenucleus

    sh o w in g excita to ry p o stsyn a p tic p o te n tia ls( )EPSPs evoked from stimulation of

    re tin o g e n icu la te a ffe re n ts via th e o p tic tra ct( )Ai Di or corticogeniculate afferents via the

    (optic radiation )Aii Dii

    Synaptic inputs to cells of the

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    A Lejeune 23

    Synaptic inputs to cells of theventral posterior medial and

    posterior medial nuclei

    orticothalamic connections in the slice ynaptic properties of layer 6 inputs to

    ( he ventral posterior medial nucleus VP1st )rder ortical inputs to the posterior medial

    We focused n two thalamic relays .One is ( he ventral posterior VP 1st )rderedial nucleus, ,which is a first order relay like

    ,the lateral geniculate nucleus and thus receivesonly a layer 6 input from cortex. The other is the( )osterior medial POm High Order nucleus ,

    - ,which is mostly a higher order relay like the,pulvinar and thusreceives inputs from both layer 5.and layer 6 of cortex

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    A Lejeune 24

    connections in the

    sliceEPSPs showing the modulator signature :paired-pulsefacilitation, graded response, mGluR component; the driversignature : paired-pulse depression, all-or none response,no mGluR component

    corticothalamic

    C o rtico th a la m ic a xo n s fro m la ye rs 5

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    A Lejeune 25

    corticothalamicpathway

    A: injection site(arrow) in BC.Also visible is theIC. The lettered

    boxes refer to thehigher power viewsin BD.B: labeled axonsrunning between

    externalandinternal capsules.C: terminalboutons of

    corticalfibers inthalamic reticular

    C o rtico th a la m ic a xo n s fro m la ye rs 5a n d 6 a re o rth o g ra d e ly la b e le d b y

    b io cytin io n to p h o re sis in to th e b a rre lcortex

    corticothalamic

    C o rtico th a la m ic a xo n s fro m la ye rs 5

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    corticothalamicpathway

    Many axons ramify inthe thalamic reticularand ventral posteriornuclei and terminatethere, but a few

    continue further to theposterior medialnucleus.D: terminalboutonsof cortical axons inthe ventral posteriormedial nucleus andPOm.Several of the largerboutons in theposterior medial

    nucleus are circled.

    C o rtico th a la m ic a xo n s fro m la ye rs 5a n d 6 a re o rth o g ra d e ly la b e le d b y

    b io cytin io n to p h o re sis in to th e b a rre lcortex

    layer 6 inputs to the

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    A Lejeune 27

    layer 6 inputs to theventral posterior (VP 1st

    Order) medial nucleusEPSPs showing the modulator signature :paired-pulsefacilitation, graded response, mGluR component; the driversignature : paired-pulse depression, all-or none response,no mGluR component

    subcortical

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    subcorticalstimulation in a cellin the ventralposterior medialnucleus

    The EPSPs evokedby low frequency

    stimulation (LFS 400 A,14 Hz for 800 ms)are blocked withapplication of MK-801

    and DNQX(top). With theseantagonists present,high-frequencystimulation (HFS, 125Hz for 800 ms) evoked

    a sustainedEPSP (middle) that isblocked by the mGluR1antagonist, LY367385(50 M, bottom).The line below the

    trace marks the time ofthe dru a lication.

    : e x a m p le o f e v o k e d E P S P s . : -p a ire d p u ls e a cilita tio n a n d g ra d e de sp o n se o f E P S P s : e v id e n c e f a n m G lu R 1 co m p o n e n t. : .c o n tro l ( )Y 3 6 7 3 8 5 5 0 M a p p lie d to th ee ll d oe s n o t sh o w a n y e ffe ct o n its m e m b ra n ep o te n tia l

    ort ca nputs to t e

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    A Lejeune 29

    ort ca nputs to t eposterior medial (POm

    HO) nucleusEPSPs showing the modulator signature :paired-pulsefacilitation, graded response, mGluR component; the driversignature : paired-pulse depression, all-or none response,no mGluR component

    stimulation of layer :A e x a m p le o f e v o ke d E P S P s

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    A Lejeune 30

    stimulation of layer6 of barrel cortex ina cell of theposterior medialnucleus

    The EPSPsevoked by LFS (13 Hzfor 600 ms; for alltraces, stimulationintensity was 150 A) areblocked with application

    of MK-801 andDNQX (top). With theseantagonists present,HFS (125 Hz for 600 ms)evoked a sustainedEPSP (2nd trace) that is

    not blocked by MPEP,an mGluR5 antagonist(30 M, 3rd trace) butis blocked by LY367385,an mGluR1 antagonist(50 M, bottom).

    :A e x a m p le o f e v o ke d E P S P s: -B p a ire d p u lse fa cilita tio n a n d g ra d e d

    resp on se of E PS Ps:C e v id e n ce o f a n m G lu R 1 co m p o n e n t

    stimulation of layer

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    s u a o o aye5 of barrel cortex ina cell of theposterior medialnucleus

    AfterblockingEPSPs with

    DNQXand MK-801,neither LFS(50 Hz for

    855 ms, top)nor HFS(125 Hz for855 ms,

    bottom)

    : e x a m p le o f e v o k e d E P S P s: -p a ire d p u ls e d e p re s sio n: - -a ll o r n o n e re sp o n s e o f E P S P s is a p p a re n t

    ro m re s p o n s e s to in c re a s in g s tim u la tio nin te n s itie s: la c k o f m G lu R c o m p o n e n t

    or-none EPSPs

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    A Lejeune 32

    or-none EPSPsfrom cells of theposterior medialnucleus

    The 3examples ofall-or-none

    responses (and ) reflectstimulationfrom layer 5,

    whereas the 5examples ofgradedresponses

    (- - - and )

    EPSPs evoked from

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    A Lejeune 33

    separate stimulation oflayers 5 and 6 of barrelcortex in the same cellof the posterior medialnucleus

    A, i and ii: paired-pulse effects, showingdepression for layer 5stimulation (Ai) and

    facilitation for layer 6stimulation (Aii).B, i and ii:recruitment

    properties, showing all-or-none response forlayer 5 stimulation (Bi)and graded responses

    for layer 6 stimulation

    EPSPs evoked fromi l i f

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    A Lejeune 34

    separate stimulation oflayers 5 and 6 of barrelcortex in the samecellof the posteriormedial nucleus

    C, i and ii:contribution ofmGluRs. Application ofDNQX and MK-801blocks EPSPs to LFS (9Hz for 755 ms) bothfrom layer 5 (Ci, top)andfrom layer 6 (Cii, top).

    HFS (125 Hz for 755 ms)evokes nothing furtherfrom layer 5 (Ci, bottom)but evokes aprolonged EPSP from

    layer 6 (Cii, middle), and

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    A Lejeune 35

    discussionEPSPs showing the modulator signature :paired-pulsefacilitation, graded response, mGluR component; the driversignature : paired-pulse depression, all-or none response,no mGluR component

    cortical

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    A Lejeune 36

    corticalcommunicationinvolvinghigher-orderthalamic relays.

    This hypothesis suggeststhat information arrivesinitially at the corticallevel after transmissionthrough a 1rst-order (FO)thalamic relay such as thelateral geniculate nucleus,ventral division of themedial geniculate nucleus(MGNv), or medial orlateral VP. Furthercorticocorticalcommunication in additionto or perhaps instead ofdirect pathways

    involves transmission viahigher-order (HO)thalamic relays, such asthe pulvinar (Pul),magnocellular division ofthe medial geniculatenucleus or the POm. Aremaining issue is the

    identity of directcorticocortical pathways

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    A Lejeune 37

    Discussion

    h is h yp o th esis su g g ests th at in fo rm atio nrrive s in itia lly a t th e co rtica l le ve l a fte r- ( )ra n sm issio n th ro u g h a 1 rst o rd e r F Oh alam ic relay su ch as th e lateral g en icu late,u cle u s v e n tra l d iv isio n o f th e m e d ia l( ) ,e n icu la te n u cle u s M G N v o r m e d ia l o r.ate ral V Pu rth e r co rtico co rtica l o m m u n ica tio n ind d itio n to o r p e rh a p s in ste a d o f d ire ct

    -ath w ays in volves tran sm ission via h ig h er( ) ,rd er H O th a la m ic re lays su ch a s th e( ) ,u lv in a r P u l m a g n o ce llu la r d iv isio n o f th e.e d ia l g e n icu la te n u cle u s o r th e P O mrem ain in g issu e is th e id en tity o f d irectco rtico co rtica l a th w ays a s d rive r o r

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    ReviewThalamic Relay Functionsand Their Role inCorticocorticalCommunication:Generalizations from theVisual SystemR.W. Guillery1 andS.Murray Sherman2, ,1Department of Anatomy,University of WisconsinSchool of Medicine, 1300University Avenue,Madison, WI 53706 USA

    2Department ofNeurobiology, StateUniversity of New York,Stony Brook, NY 11794USAAvailable online 22January 2002.

    Questions

    http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WSS-4502BN2-5&_user=1072191&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1137422834&_rerunOrigin=google&_acct=C000051289&_version=1&_urlVersion=0&_userid=1072191&md5=77f182966760051ebc5adb9193917803%23aff1http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WSS-4502BN2-5&_user=1072191&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1137422834&_rerunOrigin=google&_acct=C000051289&_version=1&_urlVersion=0&_userid=1072191&md5=77f182966760051ebc5adb9193917803%23aff2http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WSS-4502BN2-5&_user=1072191&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1137422834&_rerunOrigin=google&_acct=C000051289&_version=1&_urlVersion=0&_userid=1072191&md5=77f182966760051ebc5adb9193917803%23aff2http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6WSS-4502BN2-5&_user=1072191&_rdoc=1&_fmt=&_orig=search&_sort=d&_docanchor=&view=c&_searchStrId=1137422834&_rerunOrigin=google&_acct=C000051289&_version=1&_urlVersion=0&_userid=1072191&md5=77f182966760051ebc5adb9193917803%23aff1
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    Questions??

    SomatosensoryCorticothalamic

    Projections:Distinguishing

    Drivers fromModulators

    par

    Iva Reichova et

    S. MurrayShermanJournal of

    Neurophysiology, 2004