The Sex-Specific The Sex-Specific Developmental Developmental

Effects of Flame Effects of Flame Retardants on Retardants on White MatterWhite Matter

Anna CotroneoAnna CotroneoColumbia High SchoolColumbia High School

Dr. Veronica Miller,Dr. Richard F. Dr. Veronica Miller,Dr. Richard F. SeegalSeegal

Wadsworth CenterWadsworth Center

•Since WWI, 80,000 new chemical compounds have been developed

•Over 3,000 have a production value over one million pounds per year

•Less then 20% of these have been tested for toxicity

•Present in everyday objects found in homes, schools, and communities

•Infants and children are most susceptible to toxic affects

•Lack of protective structure (blood brain barrier)

•Greater risk of exposure

The FactsThe Facts

PCBs

PBDEs

StructureStructure

Why PBDEs?Why PBDEs?

Studies show that PBDEs are present in serum of Studies show that PBDEs are present in serum of North American residents at 10 to 40 times North American residents at 10 to 40 times higher levels then people in Japan or Europe.higher levels then people in Japan or Europe.

Found in electronics, wire insulations, clothes Found in electronics, wire insulations, clothes and furniture foams.and furniture foams.

PBDEs are and persist in the environment and in PBDEs are and persist in the environment and in the fat of organisms bodiesthe fat of organisms bodies

Use Banned in eight statesUse Banned in eight states Still exposed through the millions of pounds Still exposed through the millions of pounds

present in consumer products.present in consumer products.

Where are PBDEs Where are PBDEs Found?Found?

Exposure Exposure

Pre/Post-natal ExposurePre/Post-natal Exposure

In Utero the In Utero the fetus is exposed fetus is exposed through the through the placentaplacenta

Post-natally the Post-natally the baby is exposed baby is exposed through breast through breast milkmilk

Lack of Lack of protective protective structures structures within the within the developing developing brain.brain.

RiskOf

Disease

Age

ADHD/Autism

Dementia

Age, sex, genetic, dietary,

environmental, immune and

endocrine factors.

0-4yrs >60yrs

ADHDADHD

•More than one million children in the United States have been diagnosed with this disorder•Anywhere from four times to nine times more prevalent in boys than in girls.

Sex Differences in ADHDSex Differences in ADHD

Girls Boys• distracted, untidy, or late with assignments.

• They frequently are accused of not listening.

• usually don’t disrupt class or prompt parent-teacher conferences.

•inability to sit still when sitting still is required,• a tendency to blurt out in class, •and poor impulse control that hurts relationships at school and home. Hyperactivity/impulsivity

Type ADHDInattentive Type ADHD

Not all boys get ADHD

Risk Factors. Sex.

Hormones.Genetics.

Immune.

Toxicants.Infections.Genetics.

The CerebellumThe Cerebellum The cerebellum The cerebellum

influences influences coordination and also coordination and also plays a role in a plays a role in a person's attention person's attention span and ability to span and ability to process things like process things like language and music. language and music.

Made up of white Made up of white matter matter

White MatterWhite Matter

White fatty substance White fatty substance through which messages through which messages are passed via insulated are passed via insulated axons.axons.

White Matter is made up White Matter is made up of astrocytes and of astrocytes and oligodendrocytes.oligodendrocytes.

When white matter is When white matter is depleted messages depleted messages cannot move as cannot move as efficiently from cell to efficiently from cell to cell.cell.

T4

OligodendrocyteAstrocytes

OPC

Immune cells that perform tasks such as transmitter reuptake and release, modulation of synaptic transmission, and the promotion of myelinating activity and nervous system repair.

Cells that insulate axons and allow for the movement of signals throughout the brain

Thyroid Hormone and Thyroid Hormone and PBDEsPBDEs

PBDEs T4

•PBDEs affect TH levels in three major ways

• Mimicking the TH and affecting synthesis

• Interfere with TH carrier proteins

• interfere with liver excretion

•Affect the hypothalamus-pituitary-thyroid axis

Review of LiteratureReview of Literature

Mount Sinani Childrens Enviornmental Heath Center. Protecting Children against Enviornmetal Threats to Health. New York, NY: Mount Sinani Childrens Health Center, 2010. Print.

•The danger of childhood expsorePBDEs Pollutuion and Prevention(OPPTS) US EPA. “US environnmental protection Agency.

• The Prevalence of PBDEs in the environment

Miller, Veronica “DEvelopmetnal PCB Exposure Induces HYpothyroxinemia and Sex-specific effects on cerebellum Glial Protein levels. International journal of Developmental Neurosciecne

•Connected the effects with ADHD

HypothesisHypothesis

Maternal Exposure to PBDEs will Maternal Exposure to PBDEs will sex-specifically decrease white sex-specifically decrease white matter and levels in developing rat matter and levels in developing rat brainsbrains

MethodsMethods

PBDE Exposure

Pregnant Long Evans Dams were exposed to either a control (corn oil) or high (34.2mg/kg/day) dose of PBDE-71. The fetuses were exposed from gestational day 6 until post-natal day 21. (first 21 days of a rats life is equal to the third trimester)

Pups were sacrificed at Post-natal day 7, 14, 21, 42

n=4 per group

Thyroid HormoneThyroid Hormone

•Circulating Serum Thyroid Hormones were measured using HPLC. I was not involved in this procedure T

4 le

vels

•PBDEs like PCBs decrease the amount of circulating TH in the brain. No differences between sexes.

IHC and ELISAIHC and ELISA

1. Block

2. Primary

3. Secondary

4. HRP

5. DAB

IHC vs ELISAIHC vs ELISA Immunohistochemistry is region Immunohistochemistry is region

specific because it is tested within specific because it is tested within the tissue prepared by sectioning the tissue prepared by sectioning half brain paraffin embedded tissue.half brain paraffin embedded tissue.

ELISAs are homogenates meaning ELISAs are homogenates meaning that it is sonicated brain tissue. It is that it is sonicated brain tissue. It is a procedure completed in wells.a procedure completed in wells.

AnalysisAnalysis

•LED microscope

•Image J software

•Measure density

• SPSS

MBPMBP

Effects of PBDEs at PND21

020406080

100120140160

1

Treatment

Mea

n M

BP Female Control

Female High

Male Control

Male High

ELISA

Effects of PBDEs at PND21

0

20

40

60

80

100

120

140

1

TreatmentM

ean

MB

P Female Control

Female High

Male Control

Male High

IHC

* *

GFAPGFAP

Effects of PBDEs at PND21

0

50

100

150

200

250

300

1

Treatment

Mea

nG

FA

P Female Control

Female High

Male Control

Male High

ELISA

**

Effects of PBDEs at PND21

0

50

100

150

200

1

TreatmentM

ean

GF

AP Female Control

Female High

Male Control

Male High

**

ResultsResults

Females

Males

•The effects in the males are significant.

•Gain MBP (Oligo)

•Lose GFAP (astrocytes)

Females

•No affects of MBP or GFAP after treatment with PBDEs

Both

•Have a decrease in TH

•Females higher then male controls

ConclusionConclusion

In conclusion we have found that

•There is not a sex difference present in the levels of TH

•There is a sex difference in the density of white matter after treatment with PBDEs in the cerebellum in MBP and GFAP

•Originally there is a sex-difference in the control animals

Future ResearchFuture Research

• To look at the mechanics between the production of TH and the eventual ending of white matter to see what is causing the difference in white matter growth

• I would like to look at Deiodinase type 3 because it is the enzyme that changes T4 to the active form T3

AcknowledgementsAcknowledgements

•Dr Richard Seegal

•Dr. Veronica Miller

•Nicole Neu, Bob Sicko

•Ms Gleason and Ms Strauss

•The other science research students

ReferencesReferencesDevelopmental neurotoxcity of PBDEs, Nova Science Publisher, 2010

Ahmed, o. A. ELgareij, A . Elbakry S. Abdesltawab “Thyroid hoemones states ans brain development interactions” ONternational Journal of Development Neuroscience 26.2 (2008):147-209. print

KandelEric R., James H,. Schwarts and thomas M Jessel. Princples of neural Science. New Touek: Mcgraw-Hill< Health Professions Divison, 2000. Print

Mount Sinani Childrens Enviornmental Heath Center. Protecting Children against Enviornmetal Threats to Health. New York, NY: Mount Sinani Childrens Health Center, 2010. Print.

PBDEs Pollutuion and Prevention(OPPTS) US EPA. “US environnmental protection Agency.