Individual differences in aged rodent models of executive function and decision making McKnight...

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Individual differences in aged rodent models of executive function and decision making

McKnight Brain Research Foundation

2014 Inter-Institutional Meeting

Barry Setlow, PhD

Dept. of Psychiatry

University of Florida College of Medicine

No financial disclosures or conflicts of interest.

Inter-temporal ChoiceInter-temporal Choice

Inter-temporal ChoiceInter-temporal Choice

delay to reward delivery

cho

ice

of

del

ayed

rew

ard

Inter-temporal ChoiceInter-temporal Choice

delay to reward delivery

cho

ice

of

del

ayed

rew

ard

addiction

Inter-temporal ChoiceInter-temporal Choice

Choice Trial

LeverOne

LeverTwo

Delay

(0, 10, 20, 40, 60 s)

Small Reward Delivery

Large Reward Delivery

No Delay

Inter-temporal choice in young and aged rats

0s 10s 20s 40s 60s0

20

40

60

80

100Young Adult (6 mo.)

Delay

% C

ho

ice

of

Lar

ge

Rew

ard

Simon et al 2010, Neurobiology of Aging

Inter-temporal choice in young and aged rats

0s 10s 20s 40s 60s0

20

40

60

80

100Young Adult (6 mo.)

Aged (24 mo.)

Delay

% C

ho

ice

of

Lar

ge

Rew

ard

Simon et al 2010, Neurobiology of Aging

Controls for reward and delay perception/responses

Reward Equalized

60s 40s 20s 10s 0s0

20

40

60

80

100Young Adult

Aged

Delay

% C

ho

ice

of

De

lay

ed R

ewar

d

Simon et al 2010, Neurobiology of Aging

Controls for reward and delay perception/responses

Reward Equalized

60s 40s 20s 10s 0s0

20

40

60

80

100Young Adult

Aged

Delay

% C

ho

ice

of

De

lay

ed R

ewar

d

Delay Equalized

0s 0s 0s 0s 0s0

20

40

60

80

100

Delay

% C

ho

ice

of

La

rge

Rew

ard

Simon et al 2010, Neurobiology of Aging

Inter-temporal choice in young and aged rats

0s 10s 20s 40s 60s0

20

40

60

80

100Young Adult (6 mo.)

Aged (24 mo.)

Delay

% C

ho

ice

of

Lar

ge

Rew

ard

Simon et al 2010, Neurobiology of Aging

Inter-temporal choice in young and aged rats

0s 10s 20s 40s 60s0

20

40

60

80

100Young Adult (6 mo.)

Aged (24 mo.)

Delay

% C

ho

ice

of

Lar

ge

Rew

ard

Simon et al 2010, Neurobiology of Aging

- similar to findings in human subjects

Individual differences in inter-Individual differences in inter-temporal choice in agingtemporal choice in aging

Individual differences ininter-temporal choice in aging

0

25

50

75

100

10 20 40 600

Delay to large reward (s)% C

ho

ice

of

larg

e, d

ela

ye

d r

ew

ard

Simon et al 2010, Neurobiology of Aging

Individual differences in inter-Individual differences in inter-temporal choice in agingtemporal choice in aging

Individual differences ininter-temporal choice in aging

0

25

50

75

100

10 20 40 600

Delay to large reward (s)% C

ho

ice

of

larg

e, d

ela

ye

d r

ew

ard

Simon et al 2010, Neurobiology of Aging

Inter-temporal choice vs.working memory

% Choice of Large Delayed RewardM

ea

n %

Co

rre

ct

(wo

rkin

g m

em

ory

)

0 20 40 60 80 10070

80

90

100

r=0.58, p<0.05

Shimp et al. in press, Neurobiol Learning & Memory

Individual differences in inter-Individual differences in inter-temporal choice in agingtemporal choice in aging

Individual differences ininter-temporal choice in aging

0

25

50

75

100

10 20 40 600

Delay to large reward (s)% C

ho

ice

of

larg

e, d

ela

ye

d r

ew

ard

Simon et al 2010, Neurobiology of Aging

- individual differences don’t account for young vs. aged differences

Inter-temporal choice vs.working memory

% Choice of Large Delayed RewardM

ea

n %

Co

rre

ct

(wo

rkin

g m

em

ory

)

0 20 40 60 80 10070

80

90

100

r=0.58, p<0.05

Shimp et al. in press, Neurobiol Learning & Memory

Age differences in inter-Age differences in inter-temporal choicetemporal choice

Hippocampus?Hippocampus?– Hippocampus implicated in inter-Hippocampus implicated in inter-

temporal choicetemporal choice

Age differences in inter-Age differences in inter-temporal choicetemporal choice

Hippocampus?Hippocampus?– Hippocampus implicated in inter-Hippocampus implicated in inter-

temporal choicetemporal choice– Some hippocampal functions decline Some hippocampal functions decline

with agewith age

Age differences in inter-Age differences in inter-temporal choicetemporal choice

Hippocampus?Hippocampus?– Hippocampus implicated in inter-Hippocampus implicated in inter-

temporal choicetemporal choice– Some hippocampal functions decline Some hippocampal functions decline

with agewith age– Age-related alterations in hippocampal Age-related alterations in hippocampal

neurochemical signalingneurochemical signaling

Age differences in inter-Age differences in inter-temporal choicetemporal choice

Hippocampus?Hippocampus?– Hippocampus implicated in inter-temporal Hippocampus implicated in inter-temporal

choicechoice– Some hippocampal functions decline with ageSome hippocampal functions decline with age– Age-related alterations in hippocampal Age-related alterations in hippocampal

neurochemical signalingneurochemical signaling– Nicotinic cholinergic receptors?Nicotinic cholinergic receptors?

Decline with ageDecline with age Decline associated with impaired hippocampal-Decline associated with impaired hippocampal-

dependent learning/memorydependent learning/memory

Age differences in inter-Age differences in inter-temporal choicetemporal choice

Dorsal Hippocampus

25 50 75 1004.5

5.0

5.5

6.0

Mean % Choice of Large Reward

4

2 n

AC

hR

Den

sity

(nC

i/mg

)

r=-.87, p<.001

α4β2 nicotinic receptors

Mendez et al 2013, Neuroscience

Age differences in inter-Age differences in inter-temporal choicetemporal choice

What does this mean?What does this mean?– an improvement in cognitive function in aging?an improvement in cognitive function in aging?

OR…OR…

Age differences in inter-Age differences in inter-temporal choicetemporal choice

What does this mean?What does this mean?– an improvement in cognitive function in aging?an improvement in cognitive function in aging?

OR…OR…– perhaps exaggerated preference for delayed perhaps exaggerated preference for delayed

gratification is not a good thinggratification is not a good thing

Age differences in inter-Age differences in inter-temporal choicetemporal choice

What does this mean?What does this mean?– an improvement in cognitive function in aging?an improvement in cognitive function in aging?

OR…OR…– perhaps exaggerated preference for delayed perhaps exaggerated preference for delayed

gratification is not a good thinggratification is not a good thing

Future directionsFuture directions– Neural/behavioral mechanismsNeural/behavioral mechanisms– Longitudinal studies (behavior and Longitudinal studies (behavior and

neuroimaging)neuroimaging)

AcknowledgementsAcknowledgementsNick Simon, PhDNick Simon, PhDSofia BeasSofia BeasIan Mendez, PhDIan Mendez, PhDKristy ShimpKristy ShimpCristina Bañuelos, PhDCristina Bañuelos, PhDMarci Mitchell, PhDMarci Mitchell, PhDCandi LaSarge, PhDCandi LaSarge, PhDKarienn Montgomery, PhDKarienn Montgomery, PhDJoanne Damborsky, PhDJoanne Damborsky, PhDCaitlin Orsini, PhDCaitlin Orsini, PhDJoseph McQuail, PhDJoseph McQuail, PhD

Dr. Jennifer BizonDr. Jennifer BizonDr. Ursula Winzer-SerhanDr. Ursula Winzer-Serhan

National Institute on AgingNational Institute on Aging

Individual differences in inter-Individual differences in inter-temporal choice in agingtemporal choice in aging

Simon et al 2010, Neurobiology of Aging

Nucleus AccumbensD2 Dopamine Receptor

40 60 80 100

0.6

0.8

1.0

1.2

% Choice of Large Delayed Reward

D2

mR

NA

Ex

pre

ss

ion

(nC

i/mg

pro

tein

)

r=0.88, p<0.01

Beas et al. in press

Inter-temporal choice vs.working memory

% Choice of Large Delayed Reward

Me

an

% C

orr

ec

t(w

ork

ing

me

mo

ry)

0 20 40 60 80 10070

80

90

100

r=0.58, p<0.05

Shimp et al. in press, Neurobiol Learning & Memory

Individual differences ininter-temporal choice in aging

0

25

50

75

100

10 20 40 600

Delay to large reward (s)% C

ho

ice

of

larg

e, d

ela

ye

d r

ew

ard

Individual differences in inter-Individual differences in inter-temporal choice in agingtemporal choice in aging

Individual differences ininter-temporal choice in aging

0

25

50

75

100

10 20 40 600

Delay to large reward (s)% C

ho

ice

of

larg

e, d

ela

ye

d r

ew

ard

Simon et al 2010, Neurobiology of Aging

Nucleus AccumbensD2 Dopamine Receptor

40 60 80 100

0.6

0.8

1.0

1.2

% Choice of Large Delayed RewardD

2 m

RN

A E

xp

res

sio

n(n

Ci/m

g p

rote

in)

r=0.88, p<0.01

Beas et al. in press

Age differences in inter-Age differences in inter-temporal choicetemporal choice

Dorsal Hippocampus

25 50 75 1004.5

5.0

5.5

6.0

Mean % Choice of Large Reward

4

2 n

AC

hR

Den

sity

(nC

i/mg

)

r=-.87, p<.001

Dorsal Hippocampus

25 50 75 100

0.4

0.6

0.8

Mean % Choice of Large Reward

7

nA

Ch

R D

ensi

ty (n

Ci/m

g)

r=-.22, p=.42

α4β2 nicotinic receptors α7 nicotinic receptors

Mendez et al 2013, Neuroscience

Control for motivational deficits

FR1 FR3 FR10 FR20 FR400

50

100

150

200

250Young Adult

Aged

Response Schedule

Le

ver

Pre

sse

s

Simon et al 2010, Neurobiology of Aging

Inter-temporal ChoiceInter-temporal Choice

delay to reward delivery

cho

ice

of

del

ayed

rew

ard

addiction0

20

40

60

80

100

0 2 4 16 32

CocaineControl

Delay (s)C

ho

ice

of

La

rge

Re

wa

rd (

%)

Mitchell et al in press, Behavioral Neuroscience

Individual differences in inter-Individual differences in inter-temporal choice in agingtemporal choice in aging

Simon et al 2010, Neurobiology of Aging

0

25

50

75

100

10 20 40 600

Delay to large reward (s)% C

ho

ice

of

larg

e, d

ela

ye

d r

ew

ard

Individual differences in inter-Individual differences in inter-temporal choice in agingtemporal choice in aging

0

25

50

75

100

10 20 40 600

Delay to large reward (s)% C

ho

ice

of

larg

e, d

ela

ye

d r

ew

ard

Simon et al 2010, Neurobiology of Aging

Nucleus AccumbensD2 Dopamine Receptor

40 60 80 100

0.6

0.8

1.0

1.2

Mean % Choice of Large Reward

D2

mR

NA

Ex

pre

ss

ion

(nC

i/mg

pro

tein

)r=0.88, p<0.01

Beas et al. in press

Individual differences in inter-Individual differences in inter-temporal choicetemporal choice

Shimp et al. in press, Neurobiology of Learning and Memory

Inter-temporal choice vs.working memory

% Choice of Large,Delayed Reward

Me

an

% C

orr

ec

t(w

ork

ing

me

mo

ry)

0 20 40 60 80 10070

80

90

100

r=0.58, p<0.05