Presentation on theme: "The Effect of Fraternal Birth Order on Motor Coordination: Developing a Model for Autism, Attention Deficit/Hyperactivity Disorder, and Dyslexia Allison."— Presentation transcript:
The Effect of Fraternal Birth Order on Motor Coordination: Developing a Model for Autism, Attention Deficit/Hyperactivity Disorder, and Dyslexia 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 3 Ronald 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 basis Dalton 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
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 (contd)
Methodology (contd) 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 (contd) Instrumentation Recorded 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 EffectFHypothesis df Error dfSig. Weight Older Siblings Sex Older Siblings * Sex No significant effects of sex and older siblings on Static Rod rotation times
Results-Transit Times EffectFHypothesis df Error dfSig. Weight Older Siblings Sex Older Siblings * Sex 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 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