Presentation on theme: "Allison S. Shaw1,2,3, Dave Putz1, and S. Marc Breedlove1"— Presentation transcript:
1Allison S. Shaw1,2,3, Dave Putz1, and S. Marc Breedlove1 The Effect of Fraternal Birth Order on Motor Coordination: Developing a Model for Autism, Attention Deficit/Hyperactivity Disorder, and DyslexiaAllison S. Shaw1,2,3, Dave Putz1, and S. Marc Breedlove11 Neuroscience Program, Michigan State University, East Lansing, MI2 College of Communication Arts and Sciences, Michigan State University, East Lansing, MI3Ronald E. McNair Post-Baccalaureate Achievement Program/Summer Research Opportunity Program, Office of Supportive Services, Michigan State University, East Lansing, MI
2Neurodevelopmental Disorders Disorders that appears early in childhoodMost common are autism, dyslexia, and attention deficit/hyperactivity disorderSuggested 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
3Maternal 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.
4Fraternal Birth OrderBlanchard & Bogaert (1996) suggest that fraternal birth order may effect fetuses in utero by a similar maternal transferThey posit that maternal immune response signals androgen release
6Fraternal Birth Order Fraternal Birth Order The birth order of male siblings bornNumerous human traits are related to fraternal birth orderFemales overlookedFemales are not affected by fraternal birth orderFemale birth order does not affect traitsSeem to be an additive affect
7Fraternal 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.)
8Motor Coordination Impaired motor coordination Ranging from inability to control movement to deficiencies in fine motor movementStatic rod is a rodent paradigm used to assess motor coordination
9This 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
10Methodology Participants 110 mice 61 males 49 females 25 older brothers36 older sisters49 females20 older brothers29 older sistersFirst litter fetuses were separated using Green Fluorescent Protein (GFP) transgene
12Green Fluorescent Protein (GFP) transgenic mice (cont’d)
13Methodology (cont’d) Procedures 5 wooden dowel rods Length: 69.5mmDiameters: 31.1, 25.6, 19.5, 15.4, 9.4mmMice taken in groups of 10All mice in group run on Rod 1 (31.1mm diameter)Placed at end of rod facing away from ledgeClock started when experimenter released mouseProcedures were repeated for Rods 2-5.
14Methodology (cont’d) Instrumentation Recorded into The Observer Time to rotate 180Time to reach line 10cm from ledgeIf the mouse fell off, default time was given (180secs.)Maximum time-180secs.
15Results-Rotation Times EffectFHypothesis dfError dfSig.Weight2.4251010.041Older Siblings1.240.296Sex0.220.959Older Siblings * Sex1.450.212No significant effects of sex and older siblings on Static Rod rotation times
16Results-Transit Times EffectFHypothesis dfError dfSig.Weight0.7651010.583Older Siblings0.380.862Sex1.040.399Older Siblings * Sex2.020.082There exists a small effect of sex and older sibling on Static Rod transit times
17Transit Times as a Function of Sex and Older Siblings secondssecondssecondssecondsseconds
20Tentative Conclusions Birth Order differentially affects motor coordination depending on sexFemales may not be affected by fraternal birth order, but instead by their male litter mates
21Future DirectionContinue behavioral testing: object recognition and novelty, gap detection, social recognition, etc.Modify model in order to better control for variabilityUse male/female sets of twins to investigate androgen response
22Acknowledgements Breedlove/Jordan Lab McNair/SROP staff McNair/SROP Natural Science Methods ClassMcNair/SROP colleaguesThis research project was funded by NIH grant MH58703