title: DOes the child with a learning disability have a biochemical defect?
abstract: SInce the brains of children with learning disabilities are not available for direct study, neurobiochemical explanations for the characteristic features exhibited by these children must necessarily be hypothetical. There is considerable evidence to show that the catecholamines, noradrenaline and dopamine, play a major role in the function of areas of the brain which mediate mood, emotional response and state of arousal. Physiological evidence of underarousal in some learning-disabled children and the dramatic effect of stimulant medication suggest that there may be a fundamental defect in catecholamine metabolism. Support for this hypothesis is provided by certain pathological studies and comparative neurochemical studies, while familial clustering of cases suggests an underlying genetic mechanism to account for the biochemical defect. However, learning-disabled children are a heterogeneous group and the postulated neurobiochemical model must be regarded merely as heuristic, for it does not have universal application.
mesh_terms: D000818:Animals; D001143:Arousal; D001921:Brain / Q000502:physiology; D001923:Brain Chemistry; D002648:Child; D004285:Dogs; D006801:Humans; D007859:Learning Disabilities / Q000209:etiology / Q000235:genetics / Q000378:metabolism* / Q000473:pathology; D008959:Models, Neurological; D018377:Neurotransmitter Agents / Q000502:physiology; D051381:Rats
chemical_list: D018377:Neurotransmitter Agents