Clumsiness and Disturbed Cerebellar Development: Insights From Animal Experiments

[摘要] Cerebellar functioning has been implied inthe fine adjustments of muscle tone, in thecoordination and the feed-forward control ofmovements and posture, as well as in theestablishment and performance of motor skills.The cerebellar cortex in mammals develops latein neuro-ontogeny and an extrapolation fromexperimental results indicates that in thehuman the proliferation of the granule cells andthe development of circuitry in the cerebellarcortex starts only in the last trimester ofpregnancy and lasts until beyond the firstbirthday. This late development makes thecerebellar development particularly vulnerableto situations like an insufficient supply ofnutrients, which may follow placental dysfunction,or to side effects of pharmacologicaltreatments like the administration of corticosteroidsin the postnatal period. We studiedwhether such situations might also lead tomotor impairments. In rats, the effects ofundernutrition during the brain growth spurtwere investigated as well as those ofcorticosteroids administered in a period that isanalogous to the7thto8thmonth of pregnancyin the human. Both these interferences affectcerebellar development and our results in ratsindicate that they also lead to retardations inthe, emergence of certain reflexes, as well as tolonger lasting motor impairments duringlocomotion. Extrapolation of these resultsstrongly suggests that a disturbed cerebellardevelopment should be considered as animportant etiological factor in clumsiness inhuman children.

[学科分类] 精神健康和精神病学