title: Excess of neurons in the human newborn mediodorsal thalamus compared with that of the adult.
abstract: The aim of this study was to quantify the total number of neurons and glial cells in the mediodorsal nucleus of the thalamus (MD) of 8 newborn human brains, in comparison to 8 adult human brains. The estimates of the cell numbers were obtained using the stereological principles of the optical fractionator. In the case of the adults, the total number of neurons in the entire MD was an average of 41% lower than in the newborn, which was statistically highly significant (P < 0.001). The estimated average total number of neurons in MD thalamus of the newborns was 11.2 million (coefficient of variation [CV] = standard deviation/mean = 0.16), compared with the adults' 6.43 million (CV = 0.15). The glial cell numbers were substantially higher in the adult brains, with an increase of almost 4 times from 10.6 million at birth to 36.3 million in the fully developed adult brain. This is the first demonstration of a higher number of human neurons in the brain of newborns compared with the adult.
authors.affiliation: Research Laboratory for Stereology and Neuroscience, Bispebjerg University Hospital, Copenhagen, Denmark.
authors.forename: Maja
authors.initials: M
authors.lastname: Abitz
authors.forename: Rune Damgaard
authors.initials: RD
authors.lastname: Nielsen
authors.forename: Edward G
authors.initials: EG
authors.lastname: Jones
authors.forename: Henning
authors.initials: H
authors.lastname: Laursen
authors.forename: Niels
authors.initials: N
authors.lastname: Graem
authors.forename: Bente
authors.initials: B
authors.lastname: Pakkenberg
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D000375:Aging / Q000473:pathology*; D002452:Cell Count; D005260:Female; D006801:Humans; D007231:Infant, Newborn; D008297:Male; D020645:Mediodorsal Thalamic Nucleus / Q000166:cytology*; D008875:Middle Aged; D009474:Neurons / Q000166:cytology*