Biomaterial Database

Allometry in the corpus callosum in neonates: Sexual dimorphism. 2022

John D Lewis, and Henriette Acosta, and Jetro J Tuulari, and Vladimir S Fonov, and D Louis Collins, and Noora M Scheinin, and Satu J Lehtola, and Aylin Rosberg, and Kristian Lidauer, and Elena Ukharova, and Jani Saunavaara, and Riitta Parkkola, and Tuire Lähdesmäki, and Linnea Karlsson, and Hasse Karlsson

Montreal Neurological Institute and Hospital, McGill University, Quebec, Canada.

The corpus callosum (CC) is the largest fiber tract in the human brain, allowing interhemispheric communication by connecting homologous areas of the two cerebral hemispheres. In adults, CC size shows a robust allometric relationship with brain size, with larger brains having larger callosa, but smaller brains having larger callosa relative to brain size. Such an allometric relationship has been shown in both males and females, with no significant difference between the sexes. But there is some evidence that there are alterations in these allometric relationships during development. However, it is currently not known whether there is sexual dimorphism in these allometric relationships from birth, or if it only develops later. We study this in neonate data. Our results indicate that there are already sex differences in these allometric relationships in neonates: male neonates show the adult-like allometric relationship between CC size and brain size; however female neonates show a significantly more positive allometry between CC size and brain size than either male neonates or female adults. The underlying cause of this sexual dimorphism is unclear; but the existence of this sexual dimorphism in neonates suggests that sex-differences in lateralization have prenatal origins.

UI	MeSH Term	Description	Entries
D007231	Infant, Newborn	An infant during the first 28 days after birth.	Neonate,Newborns,Infants, Newborn,Neonates,Newborn,Newborn Infant,Newborn Infants
D008297	Male		Males
D001921	Brain	The part of CENTRAL NERVOUS SYSTEM that is contained within the skull (CRANIUM). Arising from the NEURAL TUBE, the embryonic brain is comprised of three major parts including PROSENCEPHALON (the forebrain); MESENCEPHALON (the midbrain); and RHOMBENCEPHALON (the hindbrain). The developed brain consists of CEREBRUM; CEREBELLUM; and other structures in the BRAIN STEM.	Encephalon
D003337	Corpus Callosum	Broad plate of dense myelinated fibers that reciprocally interconnect regions of the cortex in all lobes with corresponding regions of the opposite hemisphere. The corpus callosum is located deep in the longitudinal fissure.	Interhemispheric Commissure,Neocortical Commissure,Callosum, Corpus,Callosums, Corpus,Commissure, Interhemispheric,Commissure, Neocortical,Commissures, Interhemispheric,Commissures, Neocortical,Corpus Callosums,Interhemispheric Commissures,Neocortical Commissures
D005260	Female		Females
D006801	Humans	Members of the species Homo sapiens.	Homo sapiens,Man (Taxonomy),Human,Man, Modern,Modern Man
D000328	Adult	A person having attained full growth or maturity. Adults are of 19 through 44 years of age. For a person between 19 and 24 years of age, YOUNG ADULT is available.	Adults
D012727	Sex Characteristics	Those characteristics that distinguish one SEX from the other. The primary sex characteristics are the OVARIES and TESTES and their related hormones. Secondary sex characteristics are those which are masculine or feminine but not directly related to reproduction.	Gender Characteristics,Gender Differences,Gender Dimorphism,Sex Differences,Sex Dimorphism,Sexual Dichromatism,Sexual Dimorphism,Characteristic, Gender,Characteristic, Sex,Dichromatism, Sexual,Dichromatisms, Sexual,Difference, Sex,Dimorphism, Gender,Dimorphism, Sex,Dimorphism, Sexual,Gender Characteristic,Gender Difference,Gender Dimorphisms,Sex Characteristic,Sex Difference,Sex Dimorphisms,Sexual Dichromatisms,Sexual Dimorphisms