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8344782 
Journal Article 
Otolith formation and trace elements: a theory of schizophrenic behavior 
Erway, LC 
1975 
4 
1 
16-26 
English 
Arguments and some supportive evidence have been presented for considering that the vestibular sensory system, and especially the otoliths, may be uniquely important among all the sensory organs in the development of normal, integrative functions of the brain especially the cerebellum. On this basis, it is argued that any genetic or environmental factors which alter the normal development or maintenance of this elaborate, inertial guidance system may affect the development of early locomotor functions. For example, several mutations are known in experimental animals to cause congenital otolith defects. In addition, manganese and zinc are related to otolith development. Moreover, there is suggestive evidence that zinc deficiency, and drugs which may chelate zinc, may also affect the stability of otolith formation. Development of righting reflexes and climbing ability is delayed in mice or rats with otolith defects. Moreover, adult pallid mice with otolith defects exhibit some altered patterns of total activity when tested for long periods of time within their own familiar cages. On the basis of such morphological and physiological evidence for variability in otolith development in experimental animals, it is not unrealistic to assume that similar defects may occur during human development. It is worth noting that the less severe conditions which affect otolith development also permit a greater asymmetry between development of otoliths in the 2 ears. A complete absence of otoconia from both ears may be more tolerable to normal development than a disharmony of input from the 2 ears. Individuals can tolerate the absence of vestibular function in one or both ears, but apparent discordance of input from the 2 ears is almost unbearable in cases of injury or disease of an ear. Even if the development of otoliths were normal, their usefulness as a source of spatial information would be proportional to the degree of stimulation received as that individual moves and interacts with its environment, especially during formative periods of development of brain function. In this regard, vestibular function may also be relevant to various forms of sensory deprivation in mice, monkeys, and man.