title: Allometric characteristics of the developing inferior olivary nucleus of the kitten.
abstract: The allometric characteristics of the inferior olivary complex were studied in 13 kittens, which ranged in age from 39 to 125 days gestation (parturition = 62 days). The date of conception was known for 8 of the specimens whereas only the date of birth was known for the other 5 kittens. Each brain stem was serially sectioned and every tenth section was stained with cresyl-echt violet. The volume of the complete inferior olivary complex showed a curvilinear increase, with an 8% per day growth rate postnatally. The neuron diameter also showed greater increase postnatally. The diameter reached adult range by 1 month postnatally. The neuron population exhibited both prenatal and postnatal changes. There was a 35% cell decrease from 75,800 estimated cells at 49 days to 49,140 at parturition; this was followed by a 33% increase to 73,700 estimated cells by 73 days after which the population was within the adult range. The neuron density demonstrated more than a 70% decrease prenatally. This quantitative analysis of the kitten's inferior olivary complex indicates that a transient population of olivary neurons exists prenatally and that considerable maturation of olivary complex occurs postnatally.
mesh_terms: D000818:Animals; D002415:Cats; D002452:Cell Count; D009847:Olivary Nucleus / Q000166:cytology / Q000196:embryology / Q000254:growth & development*