Postnatal Change in Sulcal Length Asymmetry in Cerebrum of Cynomolgus Monkeys (Macaca fascicularis)

Abstract

The purpose of this study was to determine the timing of the onset of adult-type sulcal length asymmetry during postnatal development of the male cynomolgus monkey cerebrum. The monkey brain has already reached adult size by 3 months of age, although the body weight only represents 1/8 of the adult body weight by that time. The fronto-occipital length and the cerebral width also reached adult levels by that postnatal age with no left/right bias. Consistently, lengths of the major primary sulci reached adult levels by 3 months of age, and then decreased slightly in sexually mature monkeys (4-6.5 years of age). Asymmetry quotient analysis showed that sulcal length asymmetry patterns gradually changed during postnatal development. The male adult pattern of sulcal length asymmetry was acquired after 24 months of age. In particular, age-dependent rightward lateralization of the arcuate sulcal length was revealed during cerebral maturation by three-way ANOVA. The results suggest that the regional difference in cerebral maturation from adolescence to young adulthood modifies the sulcal morphology with characteristic asymmetric patterns in male cynomolgus monkeys.

Sexual dimorphism of sulcal morphology of the ferret cerebrum revealed by MRI-based sulcal surface morphometry

“…In our previous neuroanatomical study, a greater cortical convolution in males than in females was observed in the visual cortical area of ferrets following the completion of the primary sulcal emergence (Sawada and Watanabe, 2012 ). A regional pattern of sulcal length asymmetry was acquired in human males from adolescence to young adulthood (Blanton et al, 2001 ; Clark et al, 2010 ), as well as in cynomolgus monkeys (Sakamoto et al, 2014 ), and enhancement of sulcal length asymmetry in prefrontal and perisylvian regions during adolescence was more prominent in males than in females in humans (Blanton et al, 2001 ; Clark et al, 2010 ). Thus, sex-related change in the cortical convolution may occur at Stage 4 of the gyrification process (during adolescent to young adult periods), although its characteristics will vary depending on the species.…”

“…While sexual dimorphism of the sulcal morphology has not been fully addressed, an asymmetric pattern of the primary sulcal length is known to differ between sexes in humans (Liu et al, 2010 ) and cynomolgus monkeys (Imai et al, 2011 ). The male adult pattern of sulcal length asymmetry in those primates was acquired during adolescence to young adulthood (Clark et al, 2010 ; Sakamoto et al, 2014 ). Also, age-related changes in sulcal morphology are more prominent in males than in females (Kochunov et al, 2005 ).…”

Development of a Semimechanistic Pharmacokinetic-Pharmacodynamic Model Describing Dextroamphetamine Exposure and Striatal Dopamine Response in Rats and Nonhuman Primates following a Single Dose of Dextroamphetamine

“…Brain ECF-to-CSF clearance (Cl csf ) could not be estimated with precision, and so was fixed 2.9 ml/min in rats and 0.6 ml/min in NHPs on the basis of preliminary naïve pool analyses. These estimates are approximately an order of magnitude larger than the reported ECF bulk flows in the two species: 0.2 ml/min in rats (de Lange, 2013) and 22 ml/min in NHPs, the latter estimate scaled from the rat value using brain weight allometry [70 g brain weight for a 5 kg animal (Sakamoto et al, 2014)]. The difference is attributed to D-amphetamine clearance into nerve terminals by DAT (Sulzer et al, 2005) and metabolism in the brain, including N-hydroxylation by brain flavin-monooxygenase (Cashman et al, 1999).…”

Differential cortical laminar structure revealed by NeuN immunostaining and myeloarchitecture between sulcal and gyral regions independent of sexual dimorphisms in the ferret cerebrum

“…6). While myelination of the cerebral cortex continued to increase during adolescence to adulthood in humans (Miller et al, 2012;Shafee et al, 2015), the adult-type sulcal morphology was acquired after adolescence in humans (Clark et al, 2010) and cynomolgus monkeys (Sakamoto et al, 2014). Gyrification abnormality has been reported in human neurodevelopmental disorders such as autism (Nordahl et al, 2007;Schaer et al, 2013;Auzias et al, 2014) and schizophrenia (Gay et al, 2013;Budday et al, 2014).…”