Sex-dependent relations of grasp-reflex strengths from right and left hands to serum gonadotropin (FSH and LH) levels in human neonates with regard to cerebral lateralization.
The relation of grasp-reflex strength to serum FSH and LH levels were studied in human neonates. The grasp-reflex strengths from the right and left hands were found to be negatively linearly correlated with serum FSH level in males without familial sinistrality (-FS), but there was no significant correlations between these parameters in females. Serum LH levels were not correlated with grasp reflex in -FS neonates. The grasp-reflex strength from the right hand showed a significant negative linear correlation with LH only in +FS males. The right minus left (R-L) grasp-reflex strength decreased linearly with serum LH levels only in +FS males. These results did not support the testosterone hypothesis of cerebral lateralization. It was suggested that FSH and LH may indirectly influence the brain development according to sex and genetically pre-determined cerebral organization.
Tan
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Department of Physiology, Medical Faculty, Ataturk University, Erzurum, Turkey.
Zor
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D005260:Female; D005640:Follicle Stimulating Hormone / Q000097:blood*; D006225:Hand / Q000294:innervation / Q000502:physiology*; D006801:Humans; D007231:Infant, Newborn / Q000097:blood / Q000502:physiology*; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D012018:Reflex / Q000502:physiology*; D012727:Sex Characteristics; D013739:Testosterone / Q000097:blood
D013739:Testosterone; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone