Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 1 of 11

Appendix 3. In vivo studies of chlorpyrifos administered during gestation; effects described are only those measured after weaning. Bold indicates 

functional domain that showed effects.

Study & 

laboratory

Species & 

strain

Dose, route, 

vehicle

Dosing 

period

AChE 

inhibition

Domain Age of 

testing

Outcome, effective dose & 

gender

Notesa Doseresponseb

?

AbouDonia et 

al., 2006

Duke

Rat SD 1 mg/kg/d

dermal in 

70% ethanol

GD4-20 0-30% increase

brain (regions)

activity at 

PND90, F not 

M

Neuromotor 

function

PND90 Decreased grip time, M&F;

Decreased performance on 

inclined plane, F not M;

Used 2/sex/litter, 

(5 litters/

treatment), did not 

control for litter;

Cerebellar 

pathology

NA

Icenogle et 

al., 2004

Duke

Rat SD 1, 5 mg/kg/d 

sc in DMSO

GD9-12 Not measured Motor 

activity

PND28-42 Faster habituation in figure-8, 

5 mg/kg/d, M&F

10/sex/dose, no 

more than 1 of 

each sex from 

each litter;

ACh system 

involvement

Yes

LOEL=1 

PND28-56 Lower latencies (faster) in t- mg/kg/d

maze, early in testing, 1&5 

mg/kg/d, M&F

PND>91 Increased center crosses in 

elevated plus maze (more 

active), 5 mg/kg/d, M&F

Cognition PND28-56 No effect on t-maze 

spontaneous alternation, M&F

PND56-91 Increased radial arm maze

working & reference memory 

errors, early in training, 5

mg/kg/d, M&F

Neuromotor 

function

PND>91 No effect on acoustic startle 

reflex or prepulse inhibition, 

M&F

Anxiety & 

Emotion

PND>91 No effect on time in sides of 

elevated plus maze, M&F

BillauerHaimovitch 

et al., 2009

Israel

Mouse 

HS/lbg

1, 3, 5, 10, 

20 mg/kg/d

sc in DMSO

GD9-18 Not measured Cognition PND75 Longer latencies (slower 

learning) in Morris water 

maze, 1&3 mg/kg/d, M&F

1/sex/litter;

N varied,14-

34/dose group;

All dams dosed at 

20 mg/kg/d died

before delivery;

Nicotine & stem 

cell as treatments

No

LOEL=1 

mg/kg/d

Maximal 

effect at 3 

mg/kg/d; 

Higher

doses had no 

effect
Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 2 of 11

Study & 

laboratory

Species & 

strain

Dose, route, 

vehicle

Dosing 

period

AChE 

inhibition

Domain Age of 

testing

Outcome, effective dose & 

gender

Notesa Doseresponseb

?

Turgeman 

et al., 2011

Italy

Mouse 

HS/lbg

3 mg/kg/d GD9-18 Not measured Cognition PND80 Longer latencies (slower 

learning) in Morris water 

maze, M&F

1/sex/litter;

N=13-25/dose 

group;

Stem cells as 

treatments

NA

Laviola et 

al., 2006

Italy

Mouse, wild 

type on 

C57/Bl6 

background;

Study 

included 

reeler homoand 

heterozygous 

mice

Oxon 5 

mg/kg/d sc 

in osmostic 

pump with 

DMSO

GD14-16 Not measured Motor 

activity

PND>70 No difference in activity levels 

during habituation, before 

drug challenges

Only data from 

wild type shown

here;

Never mentions 

genders;

Oxon not parent;

Individual, as 

phenotyped, used; 

Total of 6 

litters/treatment;

ACh & DA 

system 

involvement;

Also some 

preweaning 

testing

NA

Venerosi et 

al., 2010

Italy

Mouse CD-1 6 mg/kg/d 

po in peanut 

oil

GD14-17 Not measured Anxiety & 

emotion

PND90 Increased time in tunnel 

between sides in light-dark

box, F not M;

Decreased latency to enter 

dark side (p=0.05) (increased 

anxiety), F not M;

Litter as unit;

N=6-13/dose;

5HT system 

involvement

NA

No effect on forced swimming 

task, M&F

Social 

behavior & 

maternal 

interaction

Adult F, 

after 

mating on 

postpartum 

day 8

Decreased attack behavior, 

increased social sniffing 

behavior to intruder male
Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 3 of 11

Study & 

laboratory

Species & 

strain

Dose, route, 

vehicle

Dosing 

period

AChE 

inhibition

Domain Age of 

testing

Outcome, effective dose & 

gender

Notesa Doseresponseb

?

Haviland et 

al., 2010

UWM

Mouse Swiss 

Webster

1, 5 mg/kg/d 

sc in DMSO

GD17-20 Not measured Cognition PND60-81 Slower learning of food 

recognition & position, 1&5 

mg/kg/d, F not M; 

Faster food recognition 

learning, 1 not 5 mg/kg/d, M 

not F;

Litter as unit;

N=8/sex/dose;

Thyroid 

involvement 

Yes (F only) 

LOEL=1 

mg/kg/d

In males, 5 

mg/kg/d had 

Spurious changes in no effect radial arm 

maze (says no effect, only 9 

trials)

Motor 

activity

PND60-81 No effect on foraging rate, 

M&F

Levin et 

al., 2002

Duke

Rat SD 1, 5 mg/kg/d 

sc in DMSO

GD17-20 Not measured Motor 

activity

PND28-42 Lower latencies (faster) in tmaze, early in testing, 1&5 

mg/kg/d, M&F

1/sex/dose from 

10 litters

Yes

LOEL=1 

mg/kg/d

Slower habituation in figure-8, 

1&5 mg/kg/d, F only

PND56-91 Lower latencies (faster) in 

radial arm maze during certain 

blocks only, 1&5 mg/kg/d, 

M&F

Cognition PND28-42 No effect on t-maze 

spontaneous alternation, M&F

PND56-91 Increased radial arm maze

working & reference memory 

errors, 1 mg/kg/d only, F not 

M

No

Radial arm 

maze effect 

at 1 mg/kg/d 

only

Ricceri et 

al., 2006

Italy

Mouse CD-1 3, 6 mg/kg/d 

po in peanut 

oil

Plus vehicle 

on PND11-

14

GD15-18 Dam on GD19 

(pilot study): 

40% brain ChE 

inhibition at 6 

mg/kg/d, serum 

inhibition at 

both doses 

Pup on GD19: 

no brain 

Motor 

activity

PND70 Increased crossing in open 

field, 6 mg/kg/d, only M tested

Litter as unit;

10 litters/

gestational dose

Yes 

Activity

NOEL= 3 

mg/kg/d

PND120 No effect on elevated plus 

maze activity, M&F

Anxiety& 

emotion

PND120 Decreased head dips in 

elevated plus maze (decreased 

anxiety), 3 mg/kg/d only, M 

not F

No 

Elevated 

plus maze

effect only 

at 3 mg/kg/d
Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 4 of 11

Study & 

laboratory

Species & 

strain

Dose, route, 

vehicle

Dosing 

period

AChE 

inhibition

Domain Age of 

testing

Outcome, effective dose & 

gender

Notesa Doseresponseb

?

inhibition, 

serum 

inhibition at 

both doses

Pup on PND15: 

no brain or 

serum 

inhibition

Social 

behavior & 

maternal 

interaction

PND75-80 Increased offensive posture 

behaviors, 6 mg/kg/d, only M 

tested;

No effect on non-social 

behaviors

Yes 

Aggression

NOEL=3 

mg/kg/d

PND90 No effect on induced maternal 

behaviors

Venerosi et 

al., 2006

Italy

Mouse CD-1 3, 6 mg/kg/d 

sc in peanut 

oil 

Plus vehicle 

on PND11-

14

GD15-18 Cites Ricceri 

2006 findings 

Social 

behavior & 

maternal 

interaction

PND120 Increased ultrasonic 

vocalizations, 6 mg/kg/d; only 

F tested

Increased social investigation, 

6 mg/kg/d

Litter as unit;

10 litters/ 

gestational dose

Yes

NOEL=3 

mg/kg/d

a Sample sizes and analyses refer only to behavioral measures

b Graded response across doses or else effect at higher but not lower dose(s)

M, F, Male, Female
Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 5 of 11

Appendix 3.2 In vivo studies of chlorpyrifos administered postnatally. Effects described are only those measured after weaning. Bold indicates 

functional domain showed effects.

Study & 

laboratory

Species & 

strain

Dose, route, 

vehicle

Dosing 

period

AChE 

inhibition

Domain Age of 

testing

Outcome, effective dose & 

gender

Notesa Doseresponseb

?

Dam et 

al., 2000

Duke

Rat SD 1 mg/kg/d sc 

in DMSO

PND1-4 ~60% brain 

(regions) 

inhibition in M, 

~20% in F; 

more at 2 hr 

than 4 hr after 

single dose on 

PND1

Motor 

activity

PND21, 30 Decreased open field activity 

& rearing, M not F

5-7/sex/dose;

Maybe split-litter 

dosing but not 

explicit;

Also some 

preweaning testing

NA

Levin et 

al., 2001

Duke

Rat SD 1 mg/kg/d sc 

in DMSO

PND1-4 Not measured Motor 

activity

PND28-42 Longer latencies (slower) in 

t-maze, M not F

10/sex/dose;

Split-litter dosing;

No ACh system 

involvement

NA

No effect on habituation in 

figure-8, M&F

Cognition PND28-42 No effect on t-maze 

spontaneous alternation, 

M&F

PND56-91 Increased radial arm maze

working & reference errors, 

early in training, M not F;

Decreased radial arm maze

working & reference errors, 

F not M

Adridge et 

al., 2005

Duke

Rat SD 1 mg/kg/d sc 

in DMSO

PND1-4 Not measured Cognition PND64+ Increased radial arm maze 

working & reference 

memory errors, M not F;

Decreased working memory 

errors in radial arm maze, F 

not M

9/sex/dose;

Probably split-litter 

dosing but not 

explicit

NA

Anxiety & 

emotion

PND52-53 Increased open arm time in 

elevated plus maze

(decreased anxiety), M not F

PND54 Decreased chocolate milk 

preference (anhedonia), 

M&F

Motor 

activity

PND52-53 Increased center crossings in 

elevated plus maze, M not F
Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 6 of 11

PND64+ No differences in radial arm 

maze latencies, M&F

Ricceri et 

al., 2003

Italy

Mouse CD1 1, 3 mg/kg/d 

sc in DMSO

PND1-4 20, 23% brain 

inhibition at 

low & high

dose 1 hr after 

dose on PND4; 

no inhibition at 

4, 24 hr

Motor 

activity

PND25 No effect on open field 

activity

Split-litter dosing;

n=8-18/sex/dose; 

says all mice got all 

tests but there are 

unexplained 

differences in 

sample size across 

tests;

Bonferronicorrected post-hocs 

followed ANOVA

main effects with 

p>0.05;

Also some 

preweaning testing

No, ChE & 

agonistic 

behaviors 

similar at 

both doses,

LOEL=1 

mg/kg/d

PND35-38 Increased activity at door 

opening in 2-chamber box, 

only 3 mg/kg/d tested, M&F

Anxiety &

emotion

PND38 No effect on novelty 

preference in 2-chamber box, 

only 3 mg/kg/d tested, M&F

Social 

behavior & 

maternal 

interaction

PND45 No effect investigative, 

affiliative, or soliciting 

behaviors, M&F;

Decreased self-grooming, 

1&3 mg/kg/d, M&F

Increased frequency & 

duration agonistic behavior 

sum, differs across time, 

1&3 mg/kg/d, M not F

Cognition PND60 No effect on passive 

avoidance, only M tested

Dam et 

al., 2000

Duke

Rat SD 5 mg/kg/d sc 

in DMSO

PND11-14 ~20-30% brain 

(regions) 

inhibition, 

M&F, more at 4 

hr than 2 hr 

after single 

dose on PND11

Motor 

activity

PND21, 30 Increased open field rearing 

& grooming, M&F

5-7/sex/dose;

Maybe split-litter 

dosing but not 

explicit;

Figure 3 says male 

only but gender 

differences not

significant

NA

Levin et 

al., 2001

Duke

Rat SD 5 mg/kg/d sc 

in DMSO

PND11-14 Not measured Motor 

activity

PND28-42 Longer latencies (slower) in 

t-maze, M not F

10/sex/dose;

Split-litter dosing;

ACh system 

involvement

NA

Decreased habituation 

(slower) in figure-8, M&F

Cognition PND28-42 No effect on t-maze 

spontaneous alternation, 

M&F

PND56-91 No effect on radial arm maze

working or reference 

memory, M&F
Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 7 of 11

Ricceri et 

al., 2003

Italy

Mouse CD1 1, 3 mg/kg/d 

sc in DMSO

PND11-14 No brain 

inhibition at 1, 

4, 24 hr after 

dose

Motor 

activity

PND25 Increased distance traveled 

in open field, 1&3 mg/kg/d, 

M&F

Split-litter dosing;

n=8-18/sex/dose;

says all mice got all 

tests but there are 

unexplained 

differences in 

sample size across 

tests;

Bonferronicorrected post-hocs 

followed ANOVA

main effects with 

p>0.05

Yes & No

Doseresponse on 

activity, 1 

has more 

effect on 

agonistic 

behaviors

LOEL=1 

mg/kg/d

PND35-38 Increased activity following 

door opening in 2-chamber 

box, only 3 mg/kg/d tested, 

M&F

Anxiety &

emotion

PND38 No effect on novelty 

preference in 2-chamber box, 

only 3 mg/kg/d tested, M&F

Social 

behavior & 

maternal 

interaction

PND45 No effect on investigative or 

affiliative behaviors, M&F;

Increased soliciting behavior, 

3 mg/kg/d, M&F

Increased frequency & 

duration agonistic behaviors 

throughout, 1&3 mg/kg/d, M 

not F

Cognition PND60 No effect on passive 

avoidance, only M tested

Ricceri et 

al., 2006

Italy

Mouse CD-1 1, 3 mg/kg/d 

sc in peanut 

oil

Plus vehicle 

to dam 

GD15-18

PND11-14 24 hr after last 

dose (PND15):

no brain 

inhibition, 

serum 

inhibition both 

doses

Motor 

activity

PND70 Increased crossing in open 

field, only 1st 5 min, 3

mg/kg/d, only M tested

Litter as unit;

10 litters/gestational 

dose, postnatal 

split-litter dosing;

Says anxiety effect 

in both sexes but 

not significant in 

males

Yes

NOEL=1 

mg/kg/d

(most 

endpoints)

PND120 No effect on elevated plus 

maze activity, M&F

Social 

behavior & 

maternal 

interaction

PND75-80 Increased attack behaviors, 3 

mg/kg/d, only M tested;

No effect on M non-social 

behaviors

Yes

maternal

LOEL=1 

mg/kg/d

PND90 Increased induced maternal 

behaviors, 1&3 mg/kg/d

Anxiety PND120 Increased time in open arms 

in elevated plus maze

(decreased anxiety), 3

mg/kg/d, F only

Yes

NOEL=1 

mg/kg/d

Venerosi 

et al., 

2006

Italy

Mouse CD-1 1, 3 mg/kg/d 

sc in peanut 

oil

Plus vehicle 

to dam 

GD15-18

PND11-14 Not measured, 

cites Ricceri 

2006 findings 

Social 

behavior & 

maternal 

interaction

PND120 No effect on ultrasonic 

vocalizations or social 

investigation, only F tested

Litter as unit

10 litters/gestational 

dose, postnatal 

split-litter dosing

Yes

NOEL=3 

mg/kg/d
Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 8 of 11

Venerosi 

et al., 

2008

Italy

Mouse CD-1 3 mg/kg/d sc 

in peanut oil

PND11-14 Not measured Social 

behavior & 

maternal 

interaction

PND40-45 No effect on social 

interaction with same-sex 

conspecific, M&F

Litter as unit;

Split-litter dosing,

2/sex/dose/litter;

N=15 litters;

N=9-14/dose for 

some maternal tests;

Female offspring 

mated on PND60, 

maternal tests after 

giving birth

NA

LD1-7 In lactating dams:

Longer latency to build nest;

Shorter latency to lick pups;

Increased time digging (nonmaternal behavior)

LD7 In lactating dams:

Decreased defensive, 

increased social 

investigative, & increased 

digging behaviors when 

exposed to intruder male

Anxiety & 

emotion

LD2 In lactating dams:

Faster entry & more mice 

entering light side (decreased 

anxiety)

Motor 

activity

PND40-45 Decreased distance moved 

during acclimation before 

social test, 1st time block, 

M&F

Johnson et 

al., 2009

MSU

Rat SD Incrementing 

doses: low, 1 

mg/kg/d; 

mid, 1 up to 4 

mg/kg/d; hi, 

1.5 up to 6 

mg/kg/d

Po in corn oil

PND1-21 PND20 (time 

after dose not 

given) – 14-

53% brain 

(hippocampal) 

inhibition, all 

doses 

significant;

PND30-40, mid 

& high doses 

still show 

inhibition (17-

23%);

No inhibition 

PND50;

M&F same

Cognition PND36-60 Increased radial arm maze

working memory errors, hi 

dose throughout training, all 

doses during last week, M 

only; 

Decreased radial arm maze

reference memory errors, 

middle to end of training, 

mid & hi doses, F only; 

Increased radial arm maze

reference errors, middle

week on training, mid & hi 

doses, M only

Split-litter dosing;

n=10-14/sex/dose;

Table 1 says 

PND20, not 21

Yes

LOEL=low 

dose (1 

mg/kg/d

PND1-21)

Motor 

activity

PND36-60 No effect on response time in 

radial arm maze

Carr et al., 

2001

MSU

Rat SD Incrementing 

doses: low, 3 

mg/kg/d; 

PND1-21, 

every other 

day

PND25, 30 –

14-26% brain 

(regions)

Motor 

activity

PND25, 30 Decreased open field 

activity, mid & hi, M&F

Between-litter 

dosing;

N=5 litters/dose,

Yes

Activity

NOEL=low 
Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 9 of 11

mid, 3 up to 6 

mg/kg/d; hi, 3

up to 12

mg/kg/d

Po in corn oil

inhibition at 

low dose; all 

doses 

significant, 

M&F same

2/sex from each 

litter;

Used within-litter 

factor in analysis;

Also some 

preweaning testing

dose (3 

mg/kg/d

PND1-21)

Jett et al., 

2001

JHU

Rat LE 0.3, 7 

mg/kg/d sc in 

peanut oil

PND7, 11, 

15

“preweaning 

study”

No brain 

inhibition on 

PND7 (3 hr 

after dose), 8, 

16, or 28 

Cognition PND24-28 Longer latencies to find 

platform in Morris water 

maze, 7 mg/kg/d throughout, 

0.3 mg/kg/d on day 1 

(p=0.05), M&F;

Less time spent in training 

quadrant, 7 mg/kg/d, M&F

Between-litter 

dosing after random 

culling;

N=8-10/sex/dose,

“2 or more litters 

used”;

“Postweaning” 

study not presented

Yes

NOEL or 

LOEL=0.3 

mg/kg/d 

(p=0.05)

Authors say 

both ways

a Sample sizes and analyses refer only to behavioral measures

b Graded response across doses or else effect at higher but not lower dose(s)

M, F, Male, Female
Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 10 of 11

Appendix 3.3 In vivo studies of chlorpyrifos administered during gestation and postnatally, continuous or discontinuous exposures. Effects described 

are only those measured after weaning. Bold indicates functional domain showed effects.

Study & 

laboratory

Species & 

strain

Dose, route, 

vehicle

Dosing 

period

AChE 

inhibition

Domain Age of 

testing

Outcome, effective dose & 

gender

Notesa Doseresponseb

?

Maurissen 

et al., 2000

Dow

Rat SD 0.3, 1, 5 

mg/kg/d po 

in corn oil

GD6-

LD10

Dam on GD20, 

4-5 hr after 

dose, 45% 

blood but no 

brain inhibition 

at 0.3; greater 

blood and brain 

inhibition at 

higher doses 

Neuromotor 

function

PND22 Increased auditory startle 

latency did not meet lower pvalue, 5 mg/kg/d, M&F;

“effects may have been real” 

– p-value =0.03

Litter as unit;

1/sex/litter;

N=8/sex/dose for 

delayed alternation

(same rats at both 

ages);

N=20/sex/dose for 

startle and motor 

activity (same rats 

at both ages);

alpha set at 0.02;

Also some 

preweaning tests;

Maternal toxicity at 

5 mg/kg/d

No doses 

showed 

effects using 

higher 

statistical 

PND61 No effect on auditory startle threshold

measures, M&F

Motor 

activity

PND21 and

PND60

No effect on total counts or 

habituation at either age, 

M&F;

High dose “may have had 

..slight increase in activity on 

PNDs 17, 21, and 60”

Cognition PND22-24

and 

PND61-91

No effect on spatial delayed 

alternation learning at either 

age, M&F

Braquenier 

et al., 2010

Belgium

Mouse CD10.2, 1, 5 

mg/kg/d po 

in corn oil

GD15-

LD14

Pup on PND1, 

3 hr after dose 

to dam, 14% 

brain inhibition, 

only 5 mg/kg/d 

group tested

Motor 

activity

“Adult” No effect on locomotor 

activity

1/litter for each test;

only F tested;

N=8-10/dose;

Dunnetts post hoc 

after main effect 

p<0.10

No

Effect only 

at 1 mg/kg/d

NOEL=0.2 

mg/kg/d

PND80 No effect on elevated plus 

maze total arm entries

Anxiety & 

emotion

“Adult” Decreased time in chamber 

center in light-dark box and 

decreased box switches 

(increased anxiety), 1mg/kg/d 

only;

PND80 Decreased time & entries in 

elevated plus maze open arm 

(increased anxiety), 1 

mg/kg/d only

Ricceri et 

al., 2006

Italy

Mouse CD13, 6 mg/kg/d 

po in peanut 

oil 

Plus 1, 3 

mg/kg/d sc in 

peanut oil on 

GD15-18 

“pre” plus 

PND11-14 

“post”

Dam on GD19 

(pilot study): 

40% brain ChE 

inhibition at 6 

mg/kg/d, serum 

inhibition at 

Motor 

activity

PND70 Increased crossing in open 

field, 6 mg/kg/d prenatal plus 

1, not 3 mg/kg/d, postnatal

NA

PND120 No pre-post interaction on 

elevated plus maze activity, 

M&F
Appendix 3. In vivo developmental table, Draft. Do not cite. 

Page 11 of 11

Study & 

laboratory

Species & 

strain

Dose, route, 

vehicle

Dosing 

period

AChE 

inhibition

Domain Age of 

testing

Outcome, effective dose & 

gender

Notesa Doseresponseb

?

PND11-14 both doses 

Pup on GD19: 

no brain 

inhibition, 

serum 

inhibition at 

both doses

Pup on PND15: 

no brain or 

serum 

inhibition

Anxiety & 

emotion

PND120 No pre-post interaction on 

elevated plus maze, M&F

Social 

behavior & 

maternal 

interaction

PND75-80 No pre-post interaction on 

social behaviors, M&F

PND90 No pre-post interaction on 

induced maternal behaviors

Venerosi et 

al., 2006

Italy

Mouse CD13, 6 mg/kg/d 

sc in peanut 

oil 

Plus 1, 3 

mg/kg/d sc in 

peanut oil on 

PND11-14

GD15-18

“pre” plus 

PND11-14

“post”

Cites Ricceri 

2006 findings 

Social 

behavior & 

maternal 

interaction

PND120 Increased ultrasonic 

vocalizations & social 

investigation at 6 mg/kg/d 

prenatally reversed by 1&3 

mg/kg/d postnatally

NA

a Sample sizes and analyses refer only to behavioral measures

b Graded response across doses or else effect at higher but not lower dose(s)

M, F, Male, Female