Posted by Chaste
on September 02, 2000 at 21:24:04:
Foetal Testosterone Exposure May Influence Later Susceptibility to Autism and the Postnatal Social Environment May Induce Onset.
M Drummond Donnachaidh*; Faith Drummond-Farquharson
The accelerating occurrence of autism spectrum disorders promotes a search for underlying psychobiological factors. Although several epidemiological investigations have correlated the plasticity of the immature brain with the psychopathology of autism, the mechanisms mediating changes in early brain development have remained relatively unexplored, thus there is no accepted explanation of the causes of autism and no method of prevention.
Data suggest that subcortical brain dysfunction has an important role in the attentional deficits commonly observed in autistic individuals. It has frequently been suggested that a chronically impaired attentional system promotes the distinct behavioural phenotypes of autism.
The following two proposals are made:
1. Elevated testosterone effect in utero increases susceptibility to autism, this proposal is supported by: Covert neuropathology or irregular physiological development due to disruptions of the immune system due to in utero exposure to elevated hormonal levels. (Coren, S. & Halpern, D.F. (1991)
2. Whereas susceptibility to autism may be determined by the prenatal hormonal environment, onset of autism is initiated by the postnatal social environment: Neonatal brain plasticity increases vulnerability to inappropriately structured input, thus adverse stimuli (repetitive, monotonous or bizarre stimuli) initiate an alteration in early brain development correlated with specific behavioural phenotypes depending on the timing of the insult.