Full Terms & Conditions of access and use can be found athttp://www.tandfonline.com/action/journalInformation?journalCode=itxr20

Toxin Reviews

ISSN: 1556-9543 (Print) 1556-9551 (Online) Journal homepage: http://www.tandfonline.com/loi/itxr20

Maternal exposure to atrazine induces thehippocampal cell apoptosis in mice offspring andimpairs their learning and spatial memory

Seyed Hamidreza Rastegar-Moghaddam, Abbas Mohammadipour,Mahmood Hosseini, Rahime Bargi & Alireza Ebrahimzadeh-Bideskan

To cite this article: Seyed Hamidreza Rastegar-Moghaddam, Abbas Mohammadipour, MahmoodHosseini, Rahime Bargi & Alireza Ebrahimzadeh-Bideskan (2018): Maternal exposure to atrazineinduces the hippocampal cell apoptosis in mice offspring and impairs their learning and spatialmemory, Toxin Reviews, DOI: 10.1080/15569543.2018.1466804

To link to this article: https://doi.org/10.1080/15569543.2018.1466804

Published online: 18 May 2018.

Submit your article to this journal

View related articles

View Crossmark data

RESEARCH ARTICLE

Maternal exposure to atrazine induces the hippocampal cell apoptosisin mice offspring and impairs their learning and spatial memory

Seyed Hamidreza Rastegar-Moghaddama, Abbas Mohammadipoura,b, Mahmood Hosseinic,Rahime Bargic and Alireza Ebrahimzadeh-Bideskana,b

aDepartment of Anatomy and Cell Biology, School of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran; bSchool ofMedicine, Microanatomy Research Center, Mashhad University of Medical Sciences, Mashhad, Iran; cSchool of Medicine,Neurocognitive Research Center, Mashhad University of Medical Sciences, Mashhad, Iran

ABSTRACTBackground: The atrazine is widely used in the world as herbicide. It has been shown that atra-zine can transmit from mother to their offspring via the placenta and the breast milk. Recentstudies also confirmed that atrazine has ability to damage to the central nervous system. Sincehippocampus is an important part of the brain that plays a key role in memory and learning, weevaluated the effects of atrazine exposure during pregnancy and lactation on the hippocampalcells and spatial memory in the male offspring of mice.Materials and methods: Twenty four pregnant Balb/C mice were divided into three groups ofatrazine 10mg/kg, atrazine 50mg/kg and normal saline (n¼ 8). Atrazine and normal saline weregiven by gavage to the animals. Daily treatment with atrazine or normal saline began from ges-tational day (GD) 6 and continued until postnatal day (PD) 23. At the end of the treatments,brains of the male offspring were collected and histological studies were performed to detectapoptotic cells and dark neurons (DNs) in their hippocampus. Moreover, eight male offspringfrom each group were weaned and housed until adulthood (PD75). Then, learning and spatialmemory were examined using Morris water maze (MWM) and passive avoidance (PA) tests.Results: The histological results of this study showed that apoptotic cells and DNs were signifi-cantly high in the offspring hippocampus in atrazine-exposed groups. Furthermore, the results ofthe behavioral tests indicated that learning and memory of offspring in the atrazine groups weresignificantly lower than in the normal saline group.Conclusions: Maternal exposure to atrazine during pregnancy and lactation periods increasesthe apoptotic cells and DNs in the hippocampus of the mice offspring and impairs their learningand spatial memory.

ARTICLE HISTORYReceived 10 May 2017Accepted 16 April 2018

KEYWORDSAtrazine; hippocampus;apoptosis; spatial memory;Morris water maze

1. Introduction

Today herbicides are widely used in agriculture toeliminate the weeds. Although these chemical materi-als enhance the agricultural productions but they areharmful to the organisms because of their long-termdurability in the environment (Bardullas et al. 2011, Liuet al. 2014). Atrazine (2-chloro-4-ethylamino-6-isopro-pylamino-s-triazine) known as one of the most widelyused herbicides. Reports indicate that the atrazineused in agriculture, enters the groundwater and sur-face water and threatens the health of organisms (Jinet al. 2010, Zhang et al. 2011).

Recent studies have reported detrimental effects ofatrazine. For example, some researchers have reportedthat Atrazine administration has side effects on themale genital system and inhibits the growth of

seminal vesicles and prostate (Rosenberg et al. 2008).Moreover, they reported that atrazine could reducethe testosterone level in animals.

Another study reported that oral administration ofatrazine in rodents prolonged menstrual periods,decreased luteinizing hormone (LH), as well as reduc-ing the secretion of prolactin (Rosenberg et al. 2008).

Some studies have also reported the toxic effects ofatrazine on the central nervous system.

It has been proved that chronic exposure to atra-zine can cause damage to the brain and disruptionof the brain locomotor activity in adult animals.Moreover, studies show that chronic exposure toatrazine in adult mice decreases the dopamineand serotonin levels in the brain (Rodriguez et al.2005, Lin et al. 2013, Lin et al. 2014).

CONTACT Abbas Mohammadipour Mohammadipa@mums.ac.ir Department of Anatomy and Cell Biology, School of Medicine, Mashhad Universityof Medical Sciences, Azadi Sq., Vakilabad Blvd., P.O. Box 91779-48564, Mashhad, Iran� 2018 Informa UK Limited, trading as Taylor & Francis Group

TOXIN REVIEWS, 2018https://doi.org/10.1080/15569543.2018.1466804

In addition, recent studies have confirmed that atra-zine can transmit from the mother to their offspringthrough placenta and milk. They have reported thatafter entering to the offspring body, atrazine enters tothe brain and affects important areas such as thehippocampus (Lin et al. 2014, Liu et al. 2014).

The hippocampus is one of the most importantareas in the brain which plays a key role in learningand memory (Uda et al. 2006, Yang et al. 2008).Therefore, injury to the hippocampus leads to memoryimpairment (Kim et al. 2009).

Thus, according to the neurotoxic effects of atra-zine, as well as its ability to transfer from mother tothe offspring and because of the importance of thehippocampus, this study examined the effects ofmaternal exposure to atrazine on offspring hippocam-pal neurons and their memory.

2. Materials and methods

2.1. Animals and treatments

For this study, adult male and female Balb/c mice(approximate weight 25 g) were purchased from ani-mal center in the Medical Faculty of the MashhadUniversity of medical sciences. Animals were housed instandard conditions (24 �C – 12 h of light and 12 h ofdarkness) for one week. During the study, animals hadfree access to food and water. After adaptation, maleand female mice (ratio 1:1) were placed into a cagefor mating. The presence of vaginal plug was consid-ered as gestational day 0 (GD0). Pregnant mice weredivided randomly into three groups (eight mice ineach group) including: (1) atrazine 10mg/kg, (2) atra-zine 50mg/kg, and (3) normal saline group. Daily treat-ment with atrazine or normal saline began from GD6and continued until postnatal day 23 (PD23). Atrazinewas used in this study purchased from Sigma Aldrich(St. Louis, MO, CAT No. 45330).

2.2. Histological assessment

On PD24, one male offspring from each mother wereselected randomly for histological studies. Selected off-spring were anesthetized deeply by chloroform andthen their skulls were opened and their brainsremoved. The brains were fixed in the formalin 10%for five days. Then all the brains were proceededaccording to routine histological method, embeddedin paraffin and cut in to 5mm coronal section forTUNEL and toluidine blue staining.

2.3. TUNEL staining

For detecting the apoptotic cells in the hippocampus,the sections were stained by in situ cell death detec-tion kit (Roche, Mannheim, Germany) (Lale Ataei andEbrahimzadeh-bideskan 2014).

At first, the sections were deparaffinized by xylenefor 30min and then rehydrated by a descending etha-nol concentration (100�, 90�, 70�). Afterward, the sec-tions were rinsed in 0.1M phosphate-buffered saline(PBS) for 15 and then transferred into 3% methanol/hydrogen peroxide solution in a dark chamber atroom temperature for 15min in order to blockendogenous peroxidase. Followed by rinsing withPBS, the sections were incubated with proteinase K(20 mg/ml), (Fermentase, EO0491) for 20min. After thisstage, the sections were rinsed by PBS and incubatedin the TUNEL reaction solution containing terminaldeoxynucleotidyltransferase and the labeled deoxynu-cleotide mixture at 4 �C overnight.

On the second day, the sections were rinsed in PBSand then incubated to POD for 90min. Followed byrinsing with PBS, the sections were incubated with dia-minobenzidine (DAB) solution (0.03 g DAB in 100mlPBS and 200ml H2O2/100ml PBS) for 15min at roomtemperature. After washing, background staining wasperformed using hematoxylin for 2min. Finally, thesections were dehydrated in increasing graded etha-nol, cleared in xylene, and mounted with coverslip. Inthis method, apoptotic nuclei were identified by thepresence of dark brown staining.

2.4. Toluidine blue staining

This staining was used to determine the dark neurons(DNs) in the hippocampi. Like TUNEL staining, the sec-tions were deparaffinized by xylene and rehydrated byusing decreasing graded ethanol. Next, the sectionswere washed and stained with toluidine blue for1min. After that, the sections were dehydrated,cleared, and mounted with cover slip (Sadeghiet al. 2013).

2.5. Quantification of apoptotic cells and DNs

The stained sections were photographed using a lightmicroscope (Olympus BX51, Tokyo, Japan) equippedwith a high-resolution camera, and the images weretransferred to the computer. The apoptotic cells andDNs were counted in the different areas of the hippo-campus (CA1, CA2, CA3, and dentate gyrus (DG)) usingstereological method.

2 S. H. RASTEGAR-MOGHADDAM ETAL.

Finally, the average number of apoptotic cells andDNs per unit area was calculated using the followingformula (Mohammadipour et al. 2014, Bagheri-abassiet al. 2015).

NA ¼P

Qa=f �P P

In this formula, “RQ” is the counted particlesappeared in sections, “a/f” is the area associated witheach frame of grade, and “RP” represents the totalnumber of frames.

2.6. Behavioral tests

2.6.1. Morris water maze (MWM)

To perform this test, we used eight adult male off-spring (PD75) in each group. As we explained before,in this study, we had eight pregnant mice in eachgroup. Therefore, for this test, one offspring from eachmother was selected.

MWM was performed as previously described(Hosseini et al. 2011). Briefly, a circular pool (136 cmdiameter and 60 cm high) was used in this study. Halfof the volume of the pool was filled with water (24�)and a circular platform was placed inside the northeastquadrant of the pool. This platform was not visible foranimals because it was submerged 2 cm below thewater surface.

This test was performed in six consecutive days. Inall the days of testing (exception 6th day), the plat-form was located inside the pool. On the sixth day inorder to the probe test, the platform was removedfrom the pool (Hosseini et al. 2011). At any time, eachanimal was placed within the pool from east, west,north, or south randomly.

The animals were allowed to swim 60 s and foundthe platform. Then, they were allowed stay on theplatform for 20 s to look around of the maze. Therewere some pictures on the walls and animals werecould use these pictures to identify the platform pos-ition. If animal could not find the platform after 60 sswimming, the examiner placed it on the platform andallowed it to stay on the platform for 20 s. Then, theanimal was removed from the maze and placedits cage.

The length of swimming path and the latency tofind the platform were recorded by a video track-ing system.

On the 6th day of the examination, the platformwas removed from the pool and the animals wereallowed to swim in the pool for 60 s. In this part of the

test, the time spent in the target quadrant by eachanimal was recorded.

2.6.2. Passive avoidance test

This test was performed by Shuttle box to evaluatethe passive avoidance (PA) learning and memory.This box contains two light and dark chambers withdimensions of 20� 20� 30 cm which were separatedby a door. The floor of the dark chamber was madeof stainless-steel bars and the distance between thebars was 1 cm. Electric shock was applied by a stimu-lator to the bars. The experiment consisted ofthree stages.

At first, the animals were placed in the light cham-ber of the device. After 10 seconds, the door wasopened and the latency of entering into the lightchamber was recorded. Moreover, total elapsed timein the light and dark chambers was recorded. Totaltime for each animal was 300 s.

After that once again, each animal was placed inthe light room, the door between two compartmentswas opened and the animal entered into the darkroom. After that, the door was closed and an electricshock (50Hz, 3 s, and 1mA intensity) was delivered tothe floor of the dark compartment by a stimulator.Then animal was removed from the box and placedin its cage. Three, 24 and 48 h after shock, the testwas repeated and time latency, total spent time indark chamber was recorded (Pourmotabbedet al. 2011).

2.7. Statistical analysis

Data were analyzed using SPSS software (version 16,Chicago, IL) by one-way analysis of variance (ANOVA)followed by Tukey’s test. All data were expressed asmean± SEM. p< .05 was considered statisticallysignificant.

3. Results

3.1. Results of TUNEL staining

Our results showed that in the CA1 and CA3 regions,the mean of apoptotic cells number per unit area inatrazine groups (10 and 50mg/kg) was significantlyhigher than normal saline group (p< .01 for CA1 andp< .05 for CA3) while there was no significant differ-ence between groups in the CA2 and DG regions(Figures 1 and 2).

TOXIN REVIEWS 3

3.2. Results of toluidine blue staining

Toluidine blue staining showed that in the CA1 andCA3 regions of hippocampus, the mean of DNs num-ber per unit area in atrazine groups (10 and 50mg/kg)was significantly higher than normal saline group(p< .01 for CA1 and p< .05 for CA3) while, there was

no significant difference between groups in the CA2and DG regions (Figures 3 and 4).

3.3. Behavioral results

3.3.1. Morris water maze

The results of the MWM are shown in Figures 5 and 6.The results showed that the animals in the normalsaline group found platform earlier than atrazinegroups. There were significant differences betweennormal saline group and atrazine 10 (p< .001) as wellas normal saline group compared with atrazine 50(p< .001). The results also showed that the animals ofatrazine 50 group spent a longer time to find the plat-form compared to atrazine 10 (p< .05). Comparison oftraveled distance to find the platform between groupsis shown in Figure 5(B). The animals in both atrazine10 and 50 groups traveled longer distances to reachthe platform compared to normal saline group (p< .05and p< .001, respectively). Moreover, we found a sig-nificant difference between atrazine 10 and atrazine50 groups (p< .001).

The comparison of elapsed time in target quadrantafter removing the platform (probe test) is shown inFigure 6(A). Results indicated that there was a signifi-cant difference between atrazine 50 and normal salinegroups (p< .001). However, there was no significantdifference between atrazine 10 and normal salinegroups. Moreover, difference between atrazine 10 and

Figure 2. The effects of maternal atrazine exposure duringpregnancy and lactation periods on apoptotic cell alteration inmice offspring hippocampus, the mean number of apoptoticcells per unit area was higher in CA1 (��p< .01) and CA3(�p< .05) in atrazine groups comparing to normal salinegroup. There was no significant difference between atrazine(10mg/kg) and atrazine (50mg/kg). The data are presented asthe mean± SEM.

Figure 1. Photomicrographs of the mice offspring hippocampus, maternal exposure to atrazine during pregnancy and lactationincreased apoptotic cells in the CA1 and CA3 regions of the offspring hippocampus. Arrows point the apoptotic cells. (A) CA1 nor-mal saline, (B) CA1 atrazine (10mg/kg), (C) CA1 atrazine (50mg/kg), (D) CA3 normal saline, (E) CA3 atrazine (10 mmg/kg), and (F)CA3 atrazine (50mg/kg), scale bar ¼ 100 mm.

4 S. H. RASTEGAR-MOGHADDAM ETAL.

atrazine 50 was not significant (p> .05). Comparisontraveled distance in target quadrant after removingthe platform is shown in Figure 7(B). The resultsshowed that the traveled distance in the target

Figure 3. Photomicrographs of the mouse offspring hippocampus, maternal atrazine exposure during pregnancy and lactationincreased DNs formation in the CA1 and CA3 regions of the offspring hippocampus. Arrows point the DNs. (A) CA1 normal saline,(B) CA1 atrazine (10mg/kg), (C) CA1 atrazine (50mg/kg), (D) CA3 normal saline, (E) CA3 atrazine (10 mmg/kg), and (F) CA3 atra-zine (50mg/kg), scale bar ¼ 100 mm.

Figure 4. The effects of maternal exposure to atrazine duringpregnancy and lactation on DNs formation in the male miceoffspring hippocampus, the mean number of DNs per unitarea was higher in CA1 (��p< .01) and CA3 (�p< .05) in atra-zine groups comparing to normal saline group. There was nosignificant difference between atrazine (10mg/kg) and atrazine(50mg/kg). The data are presented as the mean± SEM.

0

10

20

30

40

50(A)

(B)

Groups

Tim

e(S

ec)

Normal Saline

Atrazine 10

Atrazine 50***

***+

0

200

400

600

800

1000

1200

Groups

Dis

tanc

e(C

m)

Normal Saline

Atrazine 10

Atrazine 50*

***+++

Figure 5. Comparison of time latency (A) and traveled dis-tance (B) to find the platform between groups. �p< .05 and���p< .001 compared to normal saline group, þp< .05 andþþþp< .001 compared to atrazine 10 group.

TOXIN REVIEWS 5

quadrant in both atrazine 10 (p< .01) and 50 (p< .001)groups was lower than normal saline group, however,no significant difference was observed between thetwo atrazine treated groups.

3.3.2. Passive avoidance memory test

The results of the statistical analysis of PA test are pre-sented in Figure 7. The latency for entering to thedark chamber at 3 and 24 h after the shock in bothatrazine 10 and 50 groups was significantly less thannormal saline group (p< .05). Additionally, at 48 h afterthe shock, the latency to enter the dark in atrazine 50group was shorter than that normal saline group(p< .05). Moreover, results showed the latency in atra-zine groups at 3, 24, and 48 h after shock was not sig-nificant compared with each other (p> .05) (Figure7(A)). Comparison of the time spent in the dark cham-ber between the groups at 3 and 24 h after the shockshowed that animals in the atrazine groups spentmore time in this chamber in comparison to normalsaline group (p< .05 to p< .001) (Figure 7(B)).However, at 48 h after the shock, the animals of atra-zine 50 group spent longer time in the dark compart-ment (p< .001). There was no significant differencesbetween the two doses of atrazine at 3 and 24 h whenthe time spent in the dark chamber was compared

however, the animals of atrazine 50 group spent a lon-ger time in dark compared to atrazine 10 group at48 h after the shock (p< .05).

The comparison of duration of staying on lightcompartment is shown in Figure 7(C). This duration in3 h after the shock in atrazine group at dose of 10 wassignificantly shorter than normal saline group (p< .05).The results also showed this time at 24 h after shock-ing in the groups of atrazine at doses of 10 and50mg/kg were significantly less than normal salinegroup (p< .01 and p< .001, respectively). At 48 h afterthe shock, duration of stay on light compartment inthe group receiving 50mg/kg of atrazine was signifi-cantly lower than normal saline group (p< .001).The duration in 3 and 24 h after the shock was not sig-nificant between atrazine groups (p>.05). Finally,comparing the results in 48 h after the shockshowed a significant difference between atrazinegroups (p< .05).

4. Discussion

The aim of this study was examination of the effectsof maternal exposure to atrazine on memory and hip-pocampal cells in mice offspring.

The main way for atrazine to enter the human bodyis digestive system. In previous studies, it was reportedthat atrazine can enter ground water and surfacewater after using in agriculture and then it can enterto the human body (McConnell et al. 1997, Banks et al.2005, Gojmerac et al. 2006). According to this, oraladministration of atrazine was performed in the pre-sent study.

The results of the present study showed that oraladministration of atrazine during pregnancy andlactation leads to damage to the mice offspringhippocampus.

In this study, like other studies, it has proved thatatrazine can cross the biological barriers such as pla-centa and blood–brain barrier and transmit frommother to offspring brain (Cooper et al. 2000,Rodriguez et al. 2005, Lin et al. 2014).

Based on the results of the present study, maternalexposure to atrazine increases significantly apoptoticcells in CA1 and CA3 areas of the offspring hippocam-pus. Previous studies had reported that atrazineadministration in adult animals induces apoptosis intheir tissues. Therefore, our study confirms the otherstudies reports related to apoptotic effects of atrazineand indicates that atrazine not only induces apoptosisin the adult animal but also induces apoptosis in off-spring (Liu et al. 2006, Lenkowski et al. 2008, Zhanget al. 2011).

0

5

10

15

20

25

30

35

Groups

Tim

e(S

ec)

Normal Saline

Atrazine 10

Atrazine 50

***

0

100

200

300

400

500

600

700

Groups

Dis

tanc

e(S

ec)

Normal Saline

Atrazine 10

Atrazine 50

*****

(A)

(B)

Figure 6. Comparison of the spent time (A) and the traveleddistance (B) in target quadrant between groups, ��p< .01 and���p< .001 compared to normal saline group.

6 S. H. RASTEGAR-MOGHADDAM ETAL.

Moreover, previous studies have shown that atra-zine increases oxidative stress and on the other hand,hippocampus is sensitive to oxidative stress becauseof its high metabolic activity (Kim et al. 2009, Liuet al. 2014).

Therefore, one reason of hippocampal damage inthe present study may be due to oxidative stress.Oxidative stress can damage the cells by destroyingthe cell membrane, proteins, and DNA.

The hippocampus plays an important role in mem-ory and learning and its damage leads to memoryimpairment. Reports also have indicated that damageto the one region of the hippocampus can lead tomemory impairment. Luine et al. have reported thatmemory impairment will happen by lesion of the CA3region of the rat hippocampus (Luine et al. 1994).

Another study has also reported that animals withdamaging in CA1 area of their hippocampus, cannotfind the target quadrant in MWM (Tsien et al. 1996).

The results of the present study authenticate theresults of the previous studies. Our results showedthat maternal exposure to atrazine damage the CA1and CA3 regions in the offspring hippocampus.

Moreover, we found that learning and memorydecreased in atrazine-exposed animals. In the MWM,animals in the atrazine groups traveled more distanceand spent more time for finding the platform in com-parison to control group. In addition, after removal ofthe platform animals in the atrazine groups spent lesstime in the target quadrant than normal saline group.

Probably, this memory impairment is related to theSchaffer collateral pathway. This pathway is one of themost important pathways in the hippocampus. Fibersof the Schaffer collateral pathway are involved inmemory and sent from CA3 to CA1 (Collingridgeet al. 1983).

Moreover, there are some another things that theirdamage or functional disruption can lead to memoryimpairment. For example, NMDA receptor, orexinreceptors, calcium flux, ghrelin hormone and its MEK/ERK1/2 and PI3K/Akt pathways are involved in learningand memory performance. Therefore, atrazine mayaffect learning and memory by its toxic effects onthese receptors or hormones. However, this is justa guess and theory and it requires to morefuture studies.

(A) (B)

(C)

0

100

200

300

400

3 24 48

Time After Shock(h)

Del

ay(S

ec)

Normal Saline

Atrazine 10

Atrazine 50

* ** *

*

0

100

200

300

3 24 48

Time After Shock(h)

Tim

e In

Dar

k(S

ec)

Normal Saline

Atrazine 10

Atrazine 50

**

** ***

***

+

0

100

200

300

400

3 24 48

Time After Shock(h)

Tim

e In

Lig

ht(S

ec)

Normal Saline

Atrazine 10

Atrazine 50

***

***

***

+

Figure 7. Comparison of the latency to enter the dark (A), the time spent in the dark (B) and the time spent in the light (C) inPA test. �p< .05, ��p< .01 and ���p< .001 compared to normal saline group, þp< .05 atrazine 50 compared to atrazine10 group.

TOXIN REVIEWS 7

In the present study, no significant differenceobserved in the CA2 and DG between differentgroups. We do not know its reason but there aresome probabilities:

1. The present study conducted on a small numberof animals. If another study carried out with moreanimals, the results may differ from the results ofthe present study.

2. Cells in different regions of the hippocampus mayshow different behaviors to a toxic substance. Thecells of CA2 and DG may be resistant to atrazine.

3. May be vulnerable of the hippocampal cells in dif-ferent regions of the hippocampus is notthe same.

5. Conclusions

In conclusion, the results of the present study showthat exposure to atrazine during pregnancy and lacta-tion periods may induce DN and apoptotic cell alter-ation in mouse offspring hippocampus. Therefore,excessive use of atrazine in agriculture can cause braindamage in fetus and newborn.

Acknowledgments

The results described in this paper were from an MScstudent thesis. The authors would like to express theirsincere thanks to vice chancellor for research, MashhadUniversity of Medical Sciences for the financial support[No. 940025].

Disclosure statement

No potential conflict of interest was reported by the authors.

Funding

The authors would like to express their sincere thanks tovice chancellor for research, Mashhad University of MedicalSciences for the financial support [No. 940025].

References

Bagheri-abassi, F., et al., 2015. The effect of silver nanopar-ticles on apoptosis and dark neuron production in rathippocampus. Iranian journal of basic medical sciences, 18(7), 644.

Banks, K.E., et al., 2005. Chlorpyrifos in surface waters beforeand after a federally mandated ban. Environment inter-national, 31 (3), 351–356.

Bardullas, U., et al., 2011. Chronic atrazine exposure causesdisruption of the spontaneous locomotor activity andalters the striatal dopaminergic system of the male

Sprague-Dawley rat. Neurotoxicology and teratology, 33 (2),263–272.

Collingridge, G., et al., 1983. Excitatory amino acids in synap-tic transmission in the Schaffer collateral-commissuralpathway of the rat hippocampus. The journal of physi-ology, 334 (1), 33–46.

Cooper, R.L., et al., 2000. Atrazine disrupts the hypothalamiccontrol of pituitary-ovarian function. Toxicological sciences,53 (2), 297–307.

Gojmerac, T., et al., 2006. Evaluation of surface water pollutionwith atrazine, an endocrine disruptor chemical, in agriculturalareas of Turopolje, Croatia. Bulletin of environmental contam-ination and toxicology, 76 (3), 490–496.

Hosseini, M., et al., 2011. Chronic treatment by L-NAME differ-ently affects Morris water maze tasks in ovariectomizedand naïve female rats. Basic and clinical neuroscience, 2 (4),47–52.

Jin, Y., et al., 2010. Oxidative stress response and geneexpression with atrazine exposure in adult female zebra-fish (Danio rerio). Chemosphere, 78 (7), 846–852.

Kim, J.-S., et al., 2009. Differences in immunoreactivities of Ki-67 and doublecortin in the adult hippocampus in threestrains of mice. Acta histochemica, 111 (2), 150–156.

Lale Ataei, M. and Ebrahimzadeh-bideskan, A.R., 2014. Theeffects of nano-silver and garlic administration duringpregnancy on neuron apoptosis in rat offspring hippocam-pus. Iranian journal of basic medical sciences, 17 (6),411–418.

Lenkowski, J.R., et al., 2008. Perturbation of organogenesis bythe herbicide atrazine in the amphibian Xenopus laevis.Environmental health perspectives, 116 (2), 223.

Lin, Z., et al., 2013. Short-term atrazine exposure causesbehavioral deficits and disrupts monoaminergic systems inmale C57BL/6 mice. Neurotoxicology and teratology, 39,26–35.

Lin, Z., et al., 2014. Gestational and lactational exposure toatrazine via the drinking water causes specific behavioraldeficits and selectively alters monoaminergic systems inC57BL/6 mouse dams, juvenile and adult offspring.Toxicological sciences, 141 (1), 90–102.

Liu, W., et al., 2014. Effects of atrazine on the oxidative dam-age of kidney in Wister rats. International journal of clinicaland experimental medicine, 7 (10), 3235.

Liu, X.M., et al., 2006. Cytotoxic effects and apoptosis induc-tion of atrazine in a grass carp (Ctenopharyngodon idellus)cell line. Environmental toxicology, 21 (1), 80–89.

Luine, V., et al., 1994. Repeated stress causes reversibleimpairments of spatial memory performance. Brainresearch, 639 (1), 167–170.

McConnell, L.L., et al., 1997. Chlorpyrifos in the air and sur-face water of Chesapeake Bay: predictions of atmosphericdeposition fluxes. Environmental science & technology, 31(5), 1390–1398.

Mohammadipour, A., et al., 2014. Maternal exposure to titan-ium dioxide nanoparticles during pregnancy; impairedmemory and decreased hippocampal cell proliferation inrat offspring. Environmental toxicology and pharmacology,37 (2), 617–625.

Pourmotabbed, A., et al., 2011. Effect of prenatal pentylene-tetrazol-induced kindling on learning and memory ofmale offspring. Neuroscience, 172, 205–211.

8 S. H. RASTEGAR-MOGHADDAM ETAL.

Rodriguez, V.M., et al., 2005. Sustained exposure to thewidely used herbicide atrazine: altered function and lossof neurons in brain monoamine systems. Environmentalhealth perspectives, 113, 708–715.

Rosenberg, B.G., et al., 2008. Gestational exposureto atrazine: effects on the postnatal development of maleoffspring. Journal of andrology, 29 (3), 304–311.

Sadeghi, A., et al., 2013. The Effect of ascorbic acid and garlicadministration on lead-induced neural damage in ratOffspring's Hippocampus. Iranian journal of basic medicalsciences, 16 (2), 157.

Tsien, J.Z., et al., 1996. The essential role of hippocampalCA1 NMDA receptor-dependent synaptic plasticity in spa-tial memory. Cell, 87 (7), 1327–1338.

Uda, M., et al., 2006. Effects of chronic treadmill running onneurogenesis in the dentate gyrus of the hippocampus ofadult rat. Brain research, 1104 (1), 64–72.

Yang, W.M., et al., 2008. Novel effects of Nelumbo nucifera rhi-zome extract on memory and neurogenesis in the dentategyrus of the rat hippocampus. Neuroscience letters, 443 (2),104–107.

Zhang, X., et al., 2011. Atrazine-induced apoptosis of spleno-cytes in BALB/C mice. BMC medicine, 9 (1), 1.

TOXIN REVIEWS 9