Materials and methods2• Cell density = Hemisphere cell number/ Delimited area (µm ) x Sectrion›s

thickness (µm)

Interhemispheric difference of cell density (IDCD) was calculated by

subtracting the cell density of the directly affected hemisphere by the cell

density of the intact hemisphere.

• Handedness index (HI) post lesion = H-I/H+I from H=score of the healthy

hand on the Brinkman board task and I=score of the «affected» hand on

the Brinkman board task.

• Positive IDCD means more SMI-32 neurones visible in the lesioned

hemisphere. Negative is the reverse.

A unilateral lesion of the hand representation in the primary motor cortex or a partial hemisection of the cervical cord

in macaques affects the interhemispheric ratio of SMI-32 stained neurons in premotor cortical areas

Schmidlin E., Colangiulo R., Contestabile A., Kaeser M., Savidan J., Wyss A.-F., Hamadjida A., Rouiller E. M. Department of Medicine, Neurosciences, University of Fribourg, Swi�erland

III IV V

-0.0008

-0.0006

-0.0004

-0.0002

0

0.0002

0.0004

0.0006

0.0008

0.001

Pre-SMA(F6) SMA-proper (F3) PMv-r (F5)

Intact M1 injured monkeys Spinal cord injured monkeys

Introduction

The primary motor cortex (M1) of primates is interconnected with premotor areas, in both hemispheres, such as the rostral part of the ventral premotor cortex (PMv-r or F5) and the supplementary motor area (SMA: pre-SMA = F6 and SMA-proper = F3)). The working hypothesis was that after a unilateral lesion of M1,

there is a change of the SMI-32 positive cells ipsilesionally in PMv-r and SMA. To assess possible effects of a permanent unilateral lesion of M1 (hand region) or of an hemisection of the spinal cord (C7/C8 level) on PMv-r and SMA, a histological analysis of several macaques’ brain was performed by comparing between

the 2 hemispheres the neuron density of layers III and V in these premotor areas.

In this study, three subpopulations of adult animals were analyzed: (i) ; (ii) (two of them were treated with anti-Nogo A antibody); (iii) (three of them were treated with anti-Nogo A antibody).five intact control animals seven animals with a unilateral lesion of M1 nine macaques with a unilateral lesion of the spinal cord

Figure 2. Two photomicrographs of SMI-32 stained cells in SMA at 40x

magnification (image above, scale bar 200 µm) and 200x (image below,

scale bar 100 µm). The SMA delimitation and the layer’s parcellation

are shown.

SMA

PMv-r Mk-CE

Mk-CG

Figure 1. Schematic view of a cortical lesion (red area, left panel)

and a spinal lesion (blue area, right panel).

Results

• Intact monkeys have a li�le interhemispheric difference of cellular distribution in layer III and V of SMA and

PMv-r.

• In several injured monkeys, an interhemispheric significant cell density difference was observed (Figures 3 and

5).

• The SMI-32 cell density is more affected in F3 than in F6 (Figure 5), as expected.

• The treatment with anti-Nogo-A antibody does not seem to affect the cell density of the premotor areas.

• Five out of seven M1 injured monkeys and four out of nine spinal cord injured monkeys have a greater layer V

SMI-32 cell density in SMA in «intact» hemisphere.

• Age and functional recovery show some correlation with SMI-32 cell›s interhemispheric distribution.

Discussion

After cervical cord lesion (SCI) or M1 lesion, there was a

change of SMI-32 expression in layer V of SMA-proper, as

expressed by significant positive or negative IDCD in 5 M1

lesion monkeys and 4 SCI monkeys. In contrast, 2 out of

seven M1 lesion monkey and 5 out of 9 SCI monkeys did not

show a significant IDCD, like intact animals. Largely

comparable changes in PMv-r were observed.

Figure 8. IDCD in layer V of SMA plo�ed as a function HI post lesion. M1 injured

monkeys in red and spinal cord injured macaques in orange. The diamonds indicate

the anti-Nogo-A antibody treated monkeys.

Figure 6. IDCD in layer V of SMA was plo�ed in function of the age at sacrifice (upper panel), the extent of the lesion (middle panel) and the duration of the

recovery phase (lower panel). Intact monkeys in green, M1 injured monkeys in red and spinal cord injured macaques in orange. The diamonds indicate the anti-

Nogo-A antibody treated monkeys.

Figure 7. IDCD in layer V of SMA plo�ed as a function of to the functional recovery.

M1 injured monkeys in red and spinal cord injured macaques in orange. The

diamonds indicate the anti- Nogo-A antibody treated monkeys.

Figure 5. IDCD in layer V of F6 (dark blue), F3 (light blue) and PMvr (sky-blue) in all animals involved in the study.

Figure 3. IDCD in layer III of F6 (dark blue) and F3 (light

blue), showing a difference in M1 injured monkeys but not in

spinal cord injured monkeys. As compared, SCI has no

effect on layer III , in contrast to M1 lesion.

Intact M1 injured monkeys Spinal cord injured monkeys

-0.001

-0.0005

0

0.0005

0.001

0.0015

Mk-IC

Mk-RO

Mk-BI

Mk-SL

Mk-CG Mk-CGa Mk-AG

Pre-SMA(F6) SMA-proper (F3)

3ID

CD

(ce

ll n

umbe

r/µ

m)

CG

CP

AP

CS

CGa

CH

AM

AG

CC

R² = 0.1703

R² = 0.8734

0 5 10 15 20 25 30 35 40 45 50

Duration recovery phase (day)

GEBI

JU

VA

ROCE

SL

R² = 0.5634

R² = 0.2989

-0.0008

-0.0006

-0.0004

-0.0002

0

0.0002

0.0004

0.0006

0.0008

0.001

10 30 50 70 90 110

Duration recovery phase (day)

RO

GEBI

JU

CE

SL

VA

R² = 0.2727

-0.0008

-0.0006

-0.0004

-0.0002

0

0.0002

0.0004

0.0006

0.0008

0 20 40 60 80 100 120

Volume of the lesion (mm3)

M1 injured macaquesF3 – Layer V

Spinal cord injured macaquesF3 – Layer V

IZIRIE

RO

GEBI

JU

CE

R² = 0.5716

-0.001

-0.0008

-0.0006

-0.0004

-0.0002

0

0.0002

0.0004

0.0006

0.0008

1800 2000 2200 2400 2600 2800

Age at sacrifice (day)

IZIR

IEIC

CG

CH

CGa

AM

CP

AP

AG

CS

CC

R² = 0.4117

1200 1700 2200 2700 3200 3700 4200

Age at sacrifice (day)

CG

CH

CGa

AM

CP

AP

AG

CS

CC

R² = 0.255

0 10 20 30 40 50 60 70 80 90 100

Proportion of hemisection (%)

3ID

CD

(ce

ll n

umbe

r/µ

m)

3ID

CD

(ce

ll n

umbe

r/µ

m)

3ID

CD

(ce

ll n

umbe

r/µ

m)

GEBI

JU

VA

CG

CP

AP

CS

CGa

ROCE

SLCH

AM

AG

CC

R² = 0.3917

R² = 0.088

-0.0008

-0.0006

-0.0004

-0.0002

0

0.0002

0.0004

0.0006

20 30 40 50 60 70 80 90 100 110 120

Functional recovery (%)

3ID

CD

(ce

ll n

um

ber

/µm

)

GEBI

JU

VA

CG

CP

AP

CS

CGa

RO

CE

SLCH

AM

AG

CC

R² = 0.4569

R² = 0.0262

-0.0008

-0.0006

-0.0004

-0.0002

0

0.0002

0.0004

0.0006

0.0008

0.001

0 0.1 0.2 0.3 0.4 0.5 0.6 0.7

HI post lesion

3ID

CD

(ce

ll n

umbe

r/µ

m)

3ID

CD

(ce

ll n

umbe

r/µ

m)

Figure 4. Graphics that show the rostro-caudal gradient of cell density per histological section in layer V. An example for SMA and PMv-r

is presented for an intact (above) and an M1 injured (below) animals.

0.00000

0.00020

0.00040

0.00060

0.00080

0.00100

0.00120

Rostral Caudal

PMv-r Layer V, Mk-IU

Left hemisphere Right hemisphere

0

0.0001

0.0002

0.0003

0.0004

0.0005

0.0006

0.0007

0.0008

Rostral Caudal

SMA - Layer V, Mk-IE

Left hemisphere Right hemisphere

0.00000

0.00020

0.00040

0.00060

0.00080

0.00100

0.00120

Rostral Caudal

PMv-r Layer V, Mk-RO

Left hemisphere Right hemisphere

0

0.0002

0.0004

0.0006

0.0008

0.001

0.0012

0.0014

0.0016

0.0018

Rostral Caudal

Left hemisphere Right hemisphere

M1 in

jure

d M

aca

que

Inta

ct M

aca

que

3ID

CD

(ce

ll n

umbe

r/µ

m)

3ID

CD

(ce

ll n

umbe

r/µ

m)

3ID

CD

(ce

ll n

umbe

r/µ

m)

3ID

CD

(ce

ll n

umbe

r/µ

m)

SMA - Layer V, Mk-RO

Grant sponsors: Swiss National Science Foundation, Grants No. 31-61857.00, 310000-110005, 31003A- 132465 (EMR), PZ00P3_142258 (ES).The Swiss Primate Competence Centre for Research (SPCCR).

G37