Genetic Susceptibility (Family Studies): Leo Kauner in 1943, while studying autism, noticed common traits among parents of autistic children:
Serious-minded
Perfectionist
Lack of interest in forming relationships
Environmental Exposure: Speculated that neurotoxins interact with genes (at crucial time in development), but we are far from knowing exactly what neurotoxins come into play.
Toxins
Up to 50 known agents produce developmental toxicity in humans E.g. alcohol, cocaine, organic mercury compounds, pharmaceuticals like thalidomide and valproic acid – antiseizure medication
Exposed pregnant mother to toxins Up to 1,000 agents produce developmental toxicity in animals.Probably more, with undetectable results to a lab experimenter. Lead, Mercury, pesticides, polychlorinated biphenyls (PCBs) shown to disturb the processes of neurogenesis and migration, as well as general immune functioning
Many chemicals in use for industrial or agricultural purposes have not been tested for neuro-developmental toxicity.
Stages of Development
Neurodevelopment begins in the early embryonic stage and continues on through postnatal and even adolescence to a degree. Autistic children seem to be most prone during embryonic stages to the affects of neurotoxicity.
Processes of neuro-development:
Neurogenesis
Proliferation
Migration
Differentiation
Synapse formation
Myelination
Each process is susceptible to alteration via environmental agent interaction Day 20-25 of gestation, brain thought to be most susceptible to thalidomide (possible cause of ASD).
Participants