遺伝子発現パターンを指標にした霊長類
大脳皮質視覚野の比較解剖学
July/24/2015

TORU TAKAHATA, Ph.D.
Zhejiang University, Interdisciplinary Instituteof Neuroscience and Technology (ZIINT)Part 1.
Unique mRNA expression ofOCC1 in primate visual cortex.

INTRODUCTION
Brodmann’s “cortical area”

dorsalrostralINTRODUCTION
Cerebral cortex used to be referred as“isocortex”, based on the homogeneousstructure.

However, it has been shown that cerebral
cortex is heterogeneous in various ways, e.g.
dendritic field and the degree of plasticity.

We explored how primate cerebral cortex isheterogeneous in terms of gene expression.

Differential Display

1: FD△ (prefrontal cortex)
2: FA (primary motor cortex)
3: TE (temporal cortex)
4: OA (parietal cortex)
5: OC (occipital cortex)

RT-PCR

OCC1 is expressed preferentiallyin the occipital cortex ofprimates!
Tochitani, et al. (2001) Eur J Neurosci

OCC1 gene is expressed preferentially in macaque V1.

V2/V1
5 mm

Tochitani, et al. (2001) Eur J Neurosci

OCC1 gene is expressed preferentially in macaque V1.

Takahata, et al. (2006) Cereb Cortex

Visual pathway is especially well-developed in primates.

S: Somatosensory Cortex
A: Auditory Cortex
V: Visual Cortex

Krubitzer, (2000)

What about expression pattern of OCC1 in other species?

OCC1 expression is not abundant in V1 of non-primate mammals.

Mouse

Ferretdorsal

2 mmRabbit
dorsalrostral

Takahata et al. (2006) Cereb Cortex

OCC1 and its related genes encode extracellular matrix proteins.

What are expression patterns of OCC1-related genes?

There is a gradient between V1 and TE in the mRNA
expression of OCC1 and several other related genes.
OCC1Testican-1

Testican-2

SPARC

Takahata et.al. Cereb Cortex (2009)Quantification of the mRNA expression of OCC1related genes in 5 cortical areas (qRT-PCR)

Takahata et.al. Cereb Cortex (2009)

5-HT1B (and 2A) receptors are also preferentiallyexpressed in macaque V1

Watakabe. et.al.
Cereb Cortex(2009)

RBP (retinol binding-protein) and some other genes are
expressed in a complimentary pattern to OCC1.

OCC1

RBP

Komatsu. et.al. (2005) Cereb Cortex
Yamamori and Rockland (2006)
Neurosci. Res.

Heterogeneous gene expression in cerebral cortex of primates

Yamamori andRockland(2006) Neurosci. Res.

Associationareas
TEe.g. RBP,SPARC,PNMA1, SLIT1V1TEO

V3V4A2
S2V2

A1
S1e.g. OCC1,TES-1,TES-2, 5-HT1B,5-HT2A

How much extent is V1-selective gene expression conserved?

V1-selective gene expression is observed in New World andprosimian primates, but they are less conspicuous thanmacaques.

SQIRREL MONKEY

MARMOSETOWL MONKEYGALAGO
Takahata et.al. Cereb Cortex (2012)

V1-selective gene expression can only be observed inprimates, and the closer relatives of humans shows more
conspicuous pattern.

Takahata et.al. Cereb Cortex (2012)

There is a gradient in dendritic field size among
cortical areas.
Possible importance of areaselective gene expression

Elston (1997) Cereb Cortex

Area difference of gene
expression↓
Area difference ofdendrite extension↓
Area difference ofreceptive field↓
Hierarchy of primate
visual cortices

Part 2.
Discovery of border strips in macaque V1
through immediate-early gene expression
patterns.

Ocular dominance columns are most studied in macaques.

Rakic (1977) Philos Trans R Soc Lond B Biol Sci

Ocular dominance columns are most studied in macaques.
righthemisphere

Oculardominancecolumns(ODCs)

R L

R

left
hemispherearea 17（V1）
LRL

RL

dLGN
optic
chiasm

right
eye

left
eye

Ocular dominance columns are most studied in macaques.
righthemisphere

Oculardominancecolumns(ODCs)

R L

R

left
hemispherearea 17（V1）
L

R

×××

L×

R

L

×

dLGN
××
optic
chiasm

TTX injection
righteyeOcular dominance columns are most studied in macaques.

CO histochemistry[3H] Proline

Horton and Hocking (1998) J Neurosci

macaque V1

The expression of
immediate-earlygenes are regulated
by neuronal activity.

Illing, (2001) Audiol Neurootol

Ocular dominance columns can be studied by examining
immediate-early gene expression.
Normal binocular vision (macaque)

0.5 mmOcular dominance columns can be studied by examining
immediate-early gene expression.
Normal binocular vision (macaque)

0.5 mm21 days TTX (macaque)zif268

1 mm

c-fos

1h TTX(macaque)abc0.5 mm

Takahata, et al., (2009) Proc Natl Acad Sci USA

blobborder strip

1h TTX(macaque)blob

0.5 mmTakahata, et al., (2009) Proc Natl Acad Sci USA

Schematic changes of gene expression changes
after monocular inactivation.
NormalAcute (1-3h)

Late (>5h)

TTXTakahata, et al., (2009) Proc Natl Acad Sci USA

What is functional importance of border strips?

Lateral inhibition
between the two eyes
is required to form“binocular-disparitycoding neurons.”

Kikuchi, et al. (2009) InfoEngin

macaque, 1h TTX, layer IV, zif268

BS+--

DC: darkcolumn
PC: palecolumn
BS: border strip+This circuit may contribute to induce binocular-disparity
coding neurons?

Part 3.
Cross species comparison ofocular dominance columns.

Ocular dominance columns in New World monkeys.

Squirrel monkey
Adams and Horton (2003) Nat Neurosci

Ocular dominance columns in New World monkeys.
Owl monkey

Kaas and Casagrande, (1976) Brain Res

Ocular dominance columns in New World monkeys.
marmoset

11 mo

9 mo
3 mo
Spatz, (1989) Brain Res

Krubitzer, (2007)

Horton and Adams (2005) Phil Trans R Soc B

“Surprisingly, however, many squirrel monkeys, either lack or
partially lack ocular dominance columns, which would not be
expected if they are useful. This has led some to question
whether they serve a purpose, or are just a byproduct ofdevelopment.”

However, recent studies imply that New Worldmonkeys possess ocular dominance columns as well.

MarmosetRoe, et al. (2005) Anat Rec A

Owl monkey
Kaskan et al. (2007) Front Neurosci

Expression of immediate-early gene clearly represent
ocular dominance columns in owl monkeys!
Owl monkey, V1,24 h-monocularinactivation, ISHfor c-FOS

Takahata, et al., (2014)
Proc Natl Acad Sci USA

Layer 2/3

Layer 4

Takahata, et al. (2014)
Proc Natl Acad Sci USA

Obviously, CO staining is not good enough to conclude
absence of ODCs.

Patchy or stripe-like representation of ODCs can be
explained by computer simulation.
Owl monkey

Macaque

Tanaka (1991) Theory of oculardominance column formation:
Mathematical basis and computer
simulation. Biol CyberBorder strip-like structure was also observed in owl monkeys.
Owl monkey (1 hour-MI)

Border strip?

Takahata, et al. (2014)
Proc Natl Acad Sci USA

Summary of ocular dominance representations in owl monkey V1.

Takahata, et al. (2014) Proc Natl Acad Sci USA

ODCs and border strips were observed in galagos as well.
Galago (1 hour-MI)
contralateral to blocked eyec-FOS

V2

V1

Border strip?
500 umODCs can be revealed by immediate-earlygene expression in marmosets as well.
Marmoset, V1

Nakagami, et al. (2013) Front Neural Circuits

Previously, ODCs were thought to only present in a few primate species.

However, recent studies suggest that they are universal in primates.

Present!
Present!
Present!

Dr. Olavarria told that he showed ODC-like patches in rat V1.
Rat

Jaime Olavarria, MD.,
Ph.D.,
University of Washington

WGA-HRP injection

ODC-like pattern was even observed in rats!

Rat (24 hour-MI)
ipsilateral to the blocked eye

V1

contralateral to the blocked eye

1mm

Laing, Turecek, Takahata, Olavarria, (2014) “Eye-specific domains
correlate with patchy callosal connections in visual cortex ofLong Evans rats.” Cereb Cortex

“Notably, they are also absent in many animals withbinocular vision, such as rats.”

Currently dominant paradigm① A portion of New World monkeys
do not have ocular dominancecolumns.
② However, all of New World
monkeys are capable of stereopsis.
↓③ Therefore, ocular dominancecolumns are not functionallyimportant.

Next Questions:

How are ocular dominance important?

Why do ocular dominance columns exist?

↓Think about relationship with other modalities

1. In order to achieve
depth coding, ocularsegregation is necessary
at the first (and second)
synapses.

Principles of Neural Science: IVth Edition

Ohzawa, DeAngelis and Freeman (1996) Encoding of binocular disparity bysimple cells in the cat’s visual cortex. J Neurophysiol

2. Same (similar) profile attracts each other, and tends to make clusters.
V1 neurons
Right eye,10°,Form,
ON-Center,…

Left eye,110°,
Motion,ON-Center,…

Geniculo-cortical axons

Left eye,10°,Form,
OFF-Center,…

Right eye,20°,Form,
OFF-Center,…

Right eye,0°,Motion,OFF-Center,…

1. Same (similar) profile attracts each other, and tends to make clusters.
Right eye dominance,
30°preference

Left eye dominance,
30°preference

Right eye dominance,
50°preference

Left eye dominance,
50°preference1. Same (similar) profile attracts each other, and tends to make clusters.
Mandarin speaking,
Optogenetics major

English speaking,
Optogenetics major

Mandarin speaking,Histology major

English speaking,Histology major

ODCs and orientation columns tend to cross at a vertical angle.

Dark/bright: ODCs
Color: orientation columns
White: CO blobs

It has been suggested that neurons tend to locate and connect sothat they can minimize economy.

Chlokovskii and Koulakov. (2000) Physica A

It has been suggested that neurons tend to locate and connect sothat they can minimize economy.

The pattern of preferred orientation and ocular dominancecombined on the same picture, which is obtained in a computer
simulation minimizing the total length of connections. The
preferred orientation is coded by color. The left-eye dominatedareas are shown by a darker color.
Koulakov, A(Cold Spring Harbor Laboratory)ODCs may contribute to stereopsis via border strip circuit.

Part 4.
Ocular dominance layers?

Tree shrew (Tupaia belangeri)It has been suggested that right and left eye inputs aresegregated into layers, not columns in tree shrews.

Casagrande and Harting(1975) Brain Res

Hubel (1975) Brain Res

Right and left eye inputs are clearly segregated intolayers in LGN of tree shrews.

Conley, et al. (1984)
J Neurosci

Contralateral

Ipsilateralc-Fos

LGN layers are segregated by ON-Center/OFFCenter neurons, as well as ocular dominance.

Conway and Schiller (1983) Laminar organization of tree shrew dorsal lateral geniculatenucleus. J Neurophysiol

ON-Center/OFF-Center segregation
is maintained in V1 layers.

Fitzpatrick and Raczkowski (1990)
Proc Natl Acad Sci USA

Conley, Fitzpatrick and Diamond (1984) J Neurosci

Most of the V1 neurons are contralaterally-biased
binocular neurons.

Humphrey, Albano and Norton (1977) Brain Res

Summary
ODCs likely globally exist in all primate species.
There is border strip in V1 layer 4 that is conserved in primatespecies.
Even rats have ODCs.

Tree shrews have weird arrangement of ocular dominance andON-Center/OFF-Center neuron classes.
Do not accept all the descriptions in textbooks or Wikipedia.

Possible Future Directions

 Examine orientation domains by IEG expression in variousspecies.
 Examine orientation domains after monocular deprivation injuvenile animals.
 Examine OD domains after orientation deprivation in juvenileanimals.

Part 5.
Zhejiang University, Interdisciplinary
Institute of Neuroscience and Technology

Top 5 universities in China

浙江省・杭州市

西湖

華家池主要国等における論文数シェアの推移

主要国等におけるトップ10％論文数シェアの推移

Optical imaging

浙江大学系统神经与认知科学研究院

Electrophysiology
3000 sqm
20 labs
MRI Center
Primate Center

www.ziint.zju.edu.cnAnatomyOptogenetics

MRI

Viral Vector Core
2 Photon & Microscopy Core
Computer Cluster

PEOPLE

Anna Wang Roe(director)
Vision, Touch

Gang
Chen

Xiaodong
Chen

Lynn
HoYe
Li

3D vision, MRI

Visuo-Vestibular

NeurvascularCoupling

Cortical Lineage
2 PhotonHsin-yi
Lai

HailanHu

Toru
Takahata

Wang
Xi

Xiongjie
Yu

Engineering

Emotional
Socilal Behavior

Cortical Organization
Molecular Anatomy

Retrospenial
Attention

Audition
Auditory Attention

Parkinsons/Stroke

www.ziint.zju.edu.cn….more to come!

１・サル胎児大脳皮質で領野特異的遺伝子の探索をする
２・サル大脳皮質領野特異的遺伝子の転写調節因子を探索する
３・眼優位性カラムと方位選択性カラムの相互作用を調べる

霊長類大脳皮質に特有な生理・解剖学的特徴を明らかにする。

そしてその特徴を生み出す遺伝的基盤を明らかにする。

Acknowledgements
電気通信大学• 田中 繁 教授

University of Louisville• Dr. Heywood M. Petry

基礎生物学研究所• 山森 哲雄 教授

University of Washington• Dr. Jaime F. Olavarria

沼津高等専門学校• 宮下 真伸 准教授
Vanderbilt University• Dr. Jon H. Kaas
• Dr. Troy A. Hackett• Dr. Vivien A. Casagrande• Dr. Anna W. Roe• Animals