1 2 3 4 5Block

*

% F

ree

zin

g t

ime

Fig 1. 

Distance from soma (μm)

0 50 100

150

200

2500 50 10

015

020

025

00

2

4

6

R1P83 M *

6 M

3 M 6 M0

500

1000

1500

To

tal d

en

dri

tele

ng

th (

μm

)**

3 M 6 M0

5

10

15

20 **

3 M 6 M0

400

800

1200

1600

DC

X-I

R c

ells

****

Brd

U-I

R c

ells

A

C D

E F

3 M 6 M

G

H I

BrdU4 wROV

2-month

5-month

B

SA

M-P

8S

AM

-R1

SA

M-P

8S

AM

-R1

3 M

6 M

BrdU DCX ROV-EGFPDCX

1 2 3 4 5 6 7Block

****

% F

ree

zin

g t

ime R1 P8

Block 4

A C

n.s

R1 P8

Context Acquisition

A A

B A

C A

C

A

C A

C

A

C A

C

Day 1 2 3 4 5 6 7 8

…

…Block 1 Block 2 Block 3

Discrimination Training

LK MR1 P8

A C

n.s

A C

**Block 4

R1 P8

R1 P80.0

0.2

0.4

0.6

0.8

1.0%

Fre

ezi

ng

tim

e ** **

N

3 M 6 M

J

R1P8

R1P8

Fig 2. 

CGSK-3β Nestin-GFP Merged

Tyr216

Ser9 GFP

Tyr216

69.95%

Ser9

5.11%

GFP

E

3M 6M0

1

2

3

4 **Co-labeling of fluorescent area

GSK-3βCdk5 GSK-3βCdk50

1

2

3 *A B 3 M 6 MR1

P8R1 P8 R1 P8

GSK-3β(Phospho-Tyr216)

GSK-3β(Phospho-Ser9)

Total GSK-3β

β-actin

Cdk5

47

47 kD

47

33

43

3 M 6 M

R1P8

D

Fig 3. 

De

nd

rite

s le

ng

th (

μm

)

Re

lativ

e m

RN

A le

vel

0 50 10015

020

025

00

2

4

6

**4 wpt

Distance from soma (μm)

8 wpt

A

BrdU4 w

AAVNes-CreER mice

8 w

TAM

GSK-3βEGFP

EGFP

AAVs

B

E F G

H

I

Ctr

lO

E

EGFP

EGFP

EGFP

EGFP

BrdU

BrdU

Ctr

lO

E

4-w

pt8-

wpt

K L

4 wpt 8 wpt0

200400600800

1000

*

**

EG

FP

-po

sitiv

e c

ells

4 wpt 8 wpt0

10

20

30

Sp

ine

s /

10

μm ***

p=0.05

GFP DAPIC CtrlGSK-3β-OE

D

J

No

ma

lize

dflu

ore

sce

nce

inte

nsi

ty

a)

Ctrl GSK-3β-OENestin

b)a)

SGZ& Hilus

ML

ML

GCL

Fig 4. 

GSK-3β

DCX

GSK-3β

DCX

Ra

tio t

o β

-act

in1 2 3 4 5 6

***

AC****

Brd

U-I

R c

ells

Contextual discrimination

4-month age

6 w 2 w

SB / Vehicle

BrdU

DCX BrdU

R1-Veh R1-SB P8-Veh P8-SB

A A B AC A C A C AC AC A C …

A

D E F

G H

R1

P8

Veh SB

% F

reez

ing

time

Block

I

A B A B A B A B** ** ** **

R1 P8D

CX

-IR

ce

lls

SB SB

% F

ree

zin

g t

ime

R1 P8

A C A C A C A C** ** n.s. **

Block 4

SB SB%

Fre

ezi

ng

tim

e

47 kD

C

47

47

Total GSK-3β

Veh SB Veh SBR1 P8

GSK-3β (p-Ser9)

DCX 45

B

β-actin 43

GSK-3β (p-Tyr216)

Ser9

Tyr21

6Ser

9

Tyr21

6

Ra

tio t

o G

SK

-3β

R1 P8VehSB R1 P8

P8 P8

IPCNSC

Nes-CreER GSK-3βflox/flox

GSK-3β+/-

GSK-3β-/-

f/f +/- -/-0.0

0.1

0.2

0.3

0.4 *

4 wpt

8 wpt

3 w

pt4

wpt

8 w

pt

GSK-3βflox/flox GSK-3β+/- GSK-3β-/-

EGFP DAPI

0 5010015

020

025

0

Inte

rse

ctio

ns

3 wpt 4 wpt

8 wpt

A B C

E F G

ROV

GSK-3β

3W

Immature GC

EGFPEF1α

ROV

4W

8W

DGSK-3βflox/flox

GSK-3β+/-

GSK-3β-/-

BrdU

GSK-3βflox/flox GSK-3β+/- GSK-3β-/-

4 w

pt8

wpt

DCX BrdU (merged)

DCX

ROV

Fig 5. 

FigS1. 

P8R1

PSD95

Synapsin1

Synaptotagmin

synaptophysin

78 kD

β-actin

P8R1

3 M 6 M

64

38

95

43Syn

apsin

1

Synap

tota

gmin

Synap

toph

ysin

PSD95

Synap

sin1

Synap

tota

gmin

Synap

toph

ysin

PSD95R

atio

to

β-a

ctin

3 M 6 M

Fig S2. 

Novel object recognition

3 M 6 M

-0.4

0.0

0.4

0.8**

Object-place recognition

3 M 6 M

*3 M 6 M

012345

*

R1 P8

3 M

6 M

A B C

D E F

Fig s3. 

Veh SB Veh SB

R1 P8

PSD95

Synapsin1

Synaptotagmin

synaptophysin

Synap

sin1

Synap

tota

gmin

Synap

toph

ysin

PSD95

Synap

sin1

Synap

tota

gmin

Synap

toph

ysin

PSD950.00.51.01.52.02.5

Ra

tio t

o β

-act

in

VehSB

**

**

R1 P8