Science - 31 January 2020

Extinction groups (fig. S3, C and D, and table
S2). However, density-based cluster analysis
showed that taD2- and taD1-SPNs followed
characteristic spatial distributions across the
posterior striatum in each group (Fig. 2C). In
mice undergoing a rewarded session, each sys-
tem tended to occupy nonoverlapping areas in
the DMS, with taD1-SPNs segregated to lateral
territories (Fig. 2C, top). In animals undergoing
extinction, we found a high level of conver-
gence in DMS areas, with very few neurons
detected laterally (Fig. 2C, bottom). Extinction
mice exhibited a marked increase in the pro-
portion of taD2-SPN territories that overlapped
with functional D1-SPN areas specifically in
the DMS (Fig. 2, D and E), as well as a higher
proportion of taD1-SPN clusters sharing space
with taD2-SPNs in this same region (Fig. 2, D
and F, and table S2).

D2-SPNs in the DMS are required to encode
extinction learning

We hypothesized that recruiting activated D2-
SPNs in the DMS is directly related to inhibi-
tory learning during extinction. We selectively

removed D2-SPNs from the DMS where we

had observed high taD2- and taD1-SPN con-

fluence (Fig. 2D) through genetic ablation in

adultadora2a-Cre::drd2-eGFP hybrid mice

(Fig.2Gandfig.S4A).Afterinstrumental

training, Lesioned and Sham mice were given

a 10-min extinction learning session (day 16)

followed by an extinction test 24 hours later

(Fig. 2H). This protocol was aimed at detecting

differences on test due to deficient integration

of extinction learning 24hours earlier. D2-SPN

ablation had no effect on the initial acquisi-

tion of instrumental contingencies; both groups

showed very similar levels of performance across

sessions (Fig. 2I, left) and an indistinguishable

response structure on day 15 (Fig. 2I, right, and

table S2). Likewise, both groups similarly re-

duced lever press performance during the

10-min extinction learning session (Fig. 2J

and table S2), although performance differed

24 hours later: Lesioned mice accumulated a

higher number of presses across the session

and showed a higher average level of press-

ing and a steeper linear regression slope (Fig. 2K

and table S2). This increase in performance

was not due to an overall increase in lever press

rates but rather to recurrent and persistent

performance during the extinction session

(Fig.2L;figS4,BtoD;andtableS2).

We then analyzed the distribution of taD2-

and taD1-SPNs that accumulated in the poste-

rior striatum during the 20-min test on day 17.

We again found an increased confluence of

taD2- and taD1-SPNs in the DMS of Sham mice,

which still displayed substantial overlap de-

spite being assessed on the second day of ex-

tinction (Fig. 2M and table S2). Conversely, the

absence of D2-SPNs in Lesioned mice was as-

sociated with a high density of taD1-SPNs in the

DMS (Fig. 2, M and N, and table S2). Density

analysis in the DMS revealed that taD2- and

taD1-SPNs followed opposing density patterns

in Sham and Lesioned mice: Higher densities

of taD2-SPNs predicted low densities of taD1-

SPNs and vice versa (Fig. 2O and table S2).

D2-SPNs spatially rearrange D1-SPN plasticity

We sought to establish whether D2- and D1-

SPNs functionally interact within conver-

gent striatal territories using pharmacological

Matamaleset al.,Science 367 , 549–555 (2020) 31 January 2020 2of7

Fig. 1. Nucleosomal response
mapping reveals learning-related
territories in the striatum.(A) Mice
were trained to associate an action
(lever press) with an outcome (food
pellet). (B) Four groups of eight
mice received different levels of
instrumental conditioning. 1stC, first
Contingency. (C) Immunodetection of
phosphorylated nucleosomes
(phospho-Ser 10 -histone H3; P-H3)
identifies transcriptionally active (ta)
neurons in the posterior striatum.
P-H3 immunoreactivity was specifically
detected in the nuclei (DAPI+)of
SPNs (DARPP-32+). (D) Digitized
reconstruction of taSPNs throughout
the striatum in“Novice,”“Expert,”
and their control groups (4362 SPNs
mapped). Right panels: return maps of
inter-action-intervals (IAIs) for lever
presses (blue) and magazine checks
(orange). Each data point represents
the time delay to its preceding (x)
and succeeding (y) behavioral element.
(E) taSPN density (cells/mm^2 ) and
overall action rate in the different
training groups (eight mice per group,
both striata). (F) Identification of
taSPNs in the striatum of a trained
drd2-eGFP mouse. Arrows: taD2-SPNs
(downward) and taD1-SPNs (upward).
(G) P-H3+nuclei densities of each
neuronal type in the striatum of the
different training groups. Note the
different scale on theyaxes. *, simple
effects (table S1).

B

D

A

CE

F

G

drd2

• eGFP

Action

Outcome

D1 D2 D1 D2 D1 D2 D1 D2

x

y

L

D

Posterior

striatum

(B: ~0.0 mm)

DAPI P-H3 DARPP-32

14 8 12 16 20

Magazine

Nucleosomal

activation

Expert 1 stCCRF RR5 RR10 RR20

Instrumental training(days)

Yoked Magazine

Magazine 1 stC

Magazine

Novice

Non contingent (N.C.)

Non Contingent

P-H3

Striatum

taSPN density

Press + check /min

110100

IAl (n)

Press

500 px

Contingency

10

100

IAl (n+1)^1

0.1

10

100

IAl (n+1)^1

Novice Check

Yoked Expert

Expert

110100

IAl (n)

0.1

Novice

P-H3

Striatum

Press

Check

N.C. NoviceYoked Expert

ytisned

NPS

at

Novice Expert N.C. Yoked

Instrumental Non instrumental

50 μm

0

20

40

60

0

8

16

24

32

0

10

20

30

40

50

0

2

4

6

8

10

250 μm

P-H3

+ eGFP

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