the effect of fraternal birth order on motor coordination: developing a model for autism, attention...
DESCRIPTION
Allison S. Shaw 1,2,3 , Dave Putz 1 , and S. Marc Breedlove 1 1 Neuroscience Program, Michigan State University, East Lansing, MI 2 College of Communication Arts and Sciences, Michigan State University, East Lansing, MI - PowerPoint PPT PresentationTRANSCRIPT
The Effect of Fraternal Birth Order on Motor Coordination: Developing a Model
for Autism, Attention Deficit/Hyperactivity Disorder, and
Dyslexia
Allison S. Shaw1,2,3, Dave Putz1, and S. Marc Breedlove1
1 Neuroscience Program, Michigan State University, East Lansing, MI2 College of Communication Arts and Sciences, Michigan State
University, East Lansing, MI 3Ronald E. McNair Post-Baccalaureate Achievement
Program/Summer Research Opportunity Program, Office of Supportive Services, Michigan State University, East Lansing, MI
Neurodevelopmental Disorders Disorders that appears early in childhood Most common are autism, dyslexia, and
attention deficit/hyperactivity disorder Suggested that they have a maternal
antibody basisDalton et al. (2003) and Vincent et al.(2002)
posit that these disorders may be caused by antibodies that transfer through the placenta to the fetus and affect development
Maternal Immune Transfer
This transfer has become known as the Maternal Immune Hypothesis and has been suggested as the cause for many other traits as well.
Fraternal Birth Order
Blanchard & Bogaert (1996) suggest that fraternal birth order may effect fetuses in utero by a similar maternal transfer
They posit that maternal immune response signals androgen release
Fetal antigens
Mother’s immune system
antibodiesandrogen
Maternal Immune Hypothesis
Fraternal Birth Order Fraternal Birth Order
The birth order of male siblings born Numerous human traits are related to fraternal
birth order Females overlooked
Females are not affected by fraternal birth order Female birth order does not affect traits
Seem to be an additive affect
Fraternal Birth Order and Neurodevelopmental Disorders Autism and Dyslexia have a fraternal birth order
effect (Cohen-Baron, unpub. & Caspi, unpub.) Males with Attention Deficit/Hyperactivity
Disorder have been shown to be hypermasculinized in specific traits due to prenatal androgens, as suggested by the maternal immune hypothesis (McFadden, unpub.)
Motor Coordination
Impaired motor coordination Ranging from inability to control movement
to deficiencies in fine motor movement Static rod is a rodent paradigm used to
assess motor coordination
This is the first study to control the birth order of mice in order to develop a model that will examine the etiology of Autism, Dyslexia, and Attention Deficit/Hyperactivity Disorder
Methodology Participants
110 mice 61 males
25 older brothers 36 older sisters
49 females 20 older brothers 29 older sisters
First litter fetuses were separated using Green Fluorescent Protein (GFP) transgene
Green Fluorescent Protein (GFP) transgenic mice
Green Fluorescent Protein (GFP) transgenic mice (cont’d)
Methodology (cont’d) Procedures
5 wooden dowel rods Length: 69.5mm Diameters: 31.1, 25.6, 19.5, 15.4, 9.4mm
Mice taken in groups of 10 All mice in group run on Rod 1 (31.1mm
diameter) Placed at end of rod facing away from ledge Clock started when experimenter released mouse
Procedures were repeated for Rods 2-5.
Methodology (cont’d)
InstrumentationRecorded into The Observer
Time to rotate 180 Time to reach line 10cm from ledge
If the mouse fell off, default time was given (180secs.)
Maximum time-180secs.
Results-Rotation Times
Effect F Hypothesis df Error df Sig.
Weight 2.42 5 101 0.041
Older Siblings 1.24 5 101 0.296
Sex 0.22 5 101 0.959
Older Siblings * Sex 1.45 5 101 0.212
No significant effects of sex and older siblings on Static Rod rotation times
Results-Transit Times
Effect F Hypothesis df Error df Sig.
Weight 0.76 5 101 0.583
Older Siblings 0.38 5 101 0.862
Sex 1.04 5 101 0.399
Older Siblings * Sex 2.02 5 101 0.082
There exists a small effect of sex and older sibling on Static Rod transit times
Transit Times as a Function of Sex and Older Siblings
Older Sisters Older Brothers
145
150
155
160
165 MalesFemales
Rod 1*
Older Sisters Older Brothers
136
138
140
142
144
146
148
150
Rod 2
Older Sisters Older Brothers
154
156
158
160
162
164
166
Rod 3
Older Sisters Older Brothers
155
160
165
170
175
180
Rod 4*
Older Sisters Older Brothers
165
170
175
180
185
Rod 5
seconds seconds
seconds seconds seconds
Rod 1 *
seconds
*p< .056
**p< .034
seconds
Rod 4
Tentative Conclusions
Birth Order differentially affects motor coordination depending on sex
Females may not be affected by fraternal birth order, but instead by their male litter mates
Future Direction
Continue behavioral testing: object recognition and novelty, gap detection, social recognition, etc.
Modify model in order to better control for variability
Use male/female sets of twins to investigate androgen response
Acknowledgements
Breedlove/Jordan Lab McNair/SROP staff McNair/SROP Natural
Science Methods Class
McNair/SROP colleagues
This research project was funded by NIH grant MH58703