Regional difference in sulcal infolding progression correlated with cerebral cortical expansion in cynomolgus monkey fetuses.

The present study aimed to specify the cerebral sulci developed by cortical expansion in cynomolgus monkey fetuses. The degree of sulcal infolding was evaluated by the gyrification index (GI), which was quantified using ex vivo magnetic resonance imaging. The correlation of cortical volume with the sulcal GI was most frequent during embryonic days (EDs) 100 to 120.

Postnatal change in sulcal length asymmetry in cerebrum of cynomolgus monkeys (Macaca fascicularis).

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.

Fetal gyrification in cynomolgus monkeys: a concept of developmental stages of gyrification.

Our article summarizes a series of studies about fetal gyrification and its relation to cerebral growth in cynomolgus monkeys. Based on the cerebral growth (i.e.

Neuroanatomic and magnetic resonance imaging references for normal development of cerebral sulci of laboratory primate, cynomolgus monkeys (Macaca fascicularis).

Cynomolgus monkey (Macaca fascicularis) is a popular laboratory primate belonging to Old World monkeys, which are the group most closely related to humans except for the apes. This paper summarizes a series of our studies regarding the development of cerebral sulci and gyri in this primate, and the stated possibility of evaluation of the sulcal development for assessing the developmental toxicity testing. The cerebrum of cynomolgus monkeys experienced a regular sequence of emergence of sulci and gyri on gross observation while such timetables corresponded to those obtained by magnetic resonance imaging (MRI) with a lag time of 10-30 days.

Sexual dimorphism of sulcal length asymmetry in the cerebrum of adult cynomolgus monkeys (Macaca fascicularis).

The present study aimed to quantitatively clarify the gross anatomical asymmetry and sexual dimorphism of the cerebral hemispheres of cynomolgus monkeys. While the fronto-occipital length of the right and left cerebral hemispheres was not different between sexes, a statistically significant rightward asymmetry was detected in the cerebral width at the perisylvian region in females, but not in males (narrower width of the left side in the females). An asymmetry quotient of the sulcal lengths revealed a rightward asymmetry in the inferior occipital sulcus and a leftward asymmetry in the central and intraparietal sulci in both sexes.

Correlation between formation of the calcarine sulcus and morphological maturation of the lateral ventricle in cynomolgus monkey fetuses.

In the present study developmental changes in the cerebral sulci and volumes of subcortical and archicortical structures of the cerebrum in cynomolgus monkey fetuses were examined with T(1)-weighted magnetic resonance (MR) images in 3D. On the embryonic day (ED) 90, the lateral ventricle had still an immature vesicular shape in the occipital region of the cerebrum, and it dramatically closed its lumen by ED 100. In that period the calcarine sulcus progressively infolded from the medial surface of the cerebral hemisphere narrowing the lumen of the lateral ventricle in the occipital region.

Developmental toxicity of dibutyltin dichloride given on three consecutive days during organogenesis in cynomolgus monkeys.

We previously reported that the administration of dibutyltin dichloride (DBTCl) by nasogastric intubation during the entire period of organogenesis, days 20-50 of pregnancy, was embryolethal, but not teratogenic, in cynomolgus monkeys. The present study was conducted to further evaluate the developmental toxicity of DBTCl given to pregnant monkeys on 3 consecutive days during organogenesis. Cynomolgus monkeys were given DBTCl at 7.

Developments of sulcal pattern and subcortical structures of the forebrain in cynomolgus monkey fetuses: 7-tesla magnetic resonance imaging provides high reproducibility of gross structural changes.

The aim of this study was to spatio-temporally clarify gross structural changes in the forebrain of cynomolgus monkey fetuses using 7-tesla magnetic resonance imaging (MRI). T(1)-weighted coronal, horizontal, and sagittal MR slices of fixed left cerebral hemispheres were obtained from one male fetus at embryonic days (EDs) 70-150. The timetable for fetal sulcation by MRI was in good agreement with that by gross observations, with a lag time of 10-30 days.

Repeated-dose and reproductive toxicity of the ultraviolet absorber 2-(3',5'-di- tert-butyl-2'-hydroxyphenyl)-5-chlorobenzotriazole in rats.

2-(3',5'-Di-tert-butyl-2'-hydroxyphenyl)-5-chlorobenzotriazole (DBHCB) is widely used as an ultraviolet (UV) absorber. In this study, the repeated dose and reproductive toxicity of DBHCB was evaluated in rats. Crj:CD(SD)IGS rats were given DBHCB by gavage at 0, 2.

Development of cerebral sulci and gyri in fetuses of cynomolgus monkeys (Macaca fascicularis). II. Gross observation of the medial surface.

This study aimed to clarify chronological sequences of the appearances of sulci and gyri on the medial cerebral surface and its relation to the regional development of the cerebrum in cynomolgus monkeys. The lengths of cingulate and calcarine sulci were measured, and the ratios of these lengths to fronto-occipital length were estimated as indices of the size of the "frontoparietal" and "occipital" regions, respectively. The relative length of cingulate sulcus showed a biphasic increase: a slow phase from EDs 100 to 110, and a rapid phase from EDs 110 to 130.

Developmental toxicity of dibutyltin dichloride in cynomolgus monkeys.

Dibutyltin dichloride (DBTCl) has been shown to be teratogenic in rats. The present study was conducted to determine the teratogenic potential of DBTCl given to pregnant monkeys during the entire period of organogenesis. Cynomolgus monkeys were dosed once daily by nasogastric intubation with DBTCl at 0, 2.

Evaluation of developmental toxicity of ultraviolet absorber 2-(3',5'-di-tert-butyl-2'-hydroxyphenyl)-5-chlorobenzotriazole in rats.

2-(3',5'-Di-tert-butyl-2'-hydroxyphenyl)-5-chlorobenzotriazole (DBHCB) is widely used as a UV absorber. In this study, the developmental toxicity of DBHCB was evaluated in rats. Pregnant rats were given DBHCB at 0, 62.