Number Of Sulci Research Articles

Anatomical variations of sulci in human fetal cerebrum and its clinical significance

Introduction and Aim: Appearance of sulci and its number in the fetal cerebrum is a signal of growth and development. Chronological appearance and symmetrical development of sulci corresponds to gestational age of fetus. Few sulci can be visualized in the prenatal period to judge the growth of fetus. Any change in chronological appearance, symmetry and number of sulci in fetal cerebrum is of prime importance. Materials and Methods: Hundred and six cerebral hemispheres of 53 fetal brains of different gestational ages were collected from MGM Hospital Kalamboli and Aurangabad after institutional ethical approval to study the pattern of sulci on both sides after fixing in 10% formalin. Results: In 6 (5.6 %) cerebral hemispheres variation in appearance of sulci was observed. It was noted that there is change in number of superior temporal sulcus (STS), superior frontal sulcus (SFS), parieto-occipital sulcus (POS), calcarine sulcus (CS) and occipitotemporal sulcus (OTS) on both the sides in 6 cerebral hemispheres. Remaining 100 cerebral hemisphere showed normal, symmetrical appearance and number of sulci. Conclusion: It was observed that the fetal cerebral hemispheres which showed variations in appearance and number of sulci were associated with mother having eclampsia.

Antennal ultrastructure in Patia (Pieridae, Dismorphiinae).

In our previous work we studied the ultrastructure of the antennae of pierids through a character analysis. In this study we describe the antennal ultrastructure of three species and six subspecies of Patia focused on these traits at the intrageneric level. Patia is a genus of Dismorphiinae with the highest number of scaleless antennomeres (nudum = 11‒15). Therefore, the length of its antennal club is greater than that of any other genus of the subfamily. Several other features differentiate the species of Patia, particularly the number of sulci and pseudosulci and its contour or perimeter. A pattern was observed, especially in P. rhetes, in which the central sulci are disintegrated and surrounded by several pseudosulci in the basal antennomeres and along the club; in the medial and distal antennomeres, the pseudosulci merge to form sulci aggregates. Pseudosulci are uncommon on the distal antennomeres, even in P. rhetes. The central sulci are irregular and have a discontinuous edge when they are disaggregated and accompanied by pseudosulci; those that are elliptical and have a continuous contour, seldom have pseudosulci nearby. Another noteworthy feature is the different shapes of the distal antennomere that occur in the subspecies of P. cordillera and P. orise. In the former, this antennomere is quite elongated and ends at a point, whereas the distal one is less elongated and its apex blunt. Patia rhetes shows the lowest number of scaleless antennomeres (n = 11) while P. cordillera sspp. the largest (n = 14 or 15). The variety of the sensilla present in the Patia species does not provide specific differences, except in P. cordillera sororna where we discovered the presence of a claviform sensillum that does not present in any other species or subspecies. In our small sample size, we did not observe sexual dimorphism.

Sulcogyral pattern and sulcal count of the orbitofrontal cortex in individuals at ultra high risk for psychosis

Three types of orbitofrontal cortex (OFC) sulcogyral patterns have been identified in the general population. The distribution of these three types has been found to be altered in individuals at genetic risk of psychosis, and in patients with first episode psychosis (FEP) and chronic schizophrenia. This study aims at establishing whether altered OFC sulcogyral patterns were present in a large cohort of individuals at ultra high risk (UHR) for psychosis. OFC pattern type was classified and the number of posterior and intermediate sulci present on the surface of the OFC was counted. OFC sulcogyral type and the number of sulci were compared between controls (n=58) and UHR participants who transitioned (n=49) versus those who did not transition (n=77) to psychosis. Finally, the relationship between sulcogyral type and number of sulci with intellectual quotient (IQ), symptom severity and social functioning of UHR individuals was explored. In line with other studies conducted in chronic schizophrenia and FEP, UHR individuals who later transitioned to psychosis showed a reduced incidence of the Type I OFC on the right hemisphere compared to controls (χ2=19.847, p<0.001). These highly consistent results point towards the protective effect of possessing a Type I OFC in the right hemisphere. Furthermore, OFC sulcus counts revealed that controls presented with a higher number of posterior (right hemisphere; χ2=11.658, p=0.003) and intermediate sulci (left: χ2=6.643, p=0.036; right: χ2=11.726, p=0.020) when compared to UHR individuals. However, no associations between OFC types or sulcus count and IQ, symptoms and functioning were observed.

Gyrification in the Cerebral Cortex of Primates

The degree of cortical folding in primates has been analyzed using a gyrification index (GI). Correlation analyses of the GI with body weight, brain weight and neopallial volume show that the human data fit the general trend of the nonhuman anthropoids. Bigger primate brains exhibit a higher degree of fissurization, but a taxonomic difference that is independent of brain weight between prosimians and anthropoids has also been observed. In these regressions, anthropoids differed from prosimians by having a larger increase in gyrification for every unit increase in body or brain weight or neopallial volume. A stepwise regression also shows a prosimian-anthropoid difference. The best predictor for convolutedness in anthropoids is neocortical volume, while in prosimians it is brain weight. The GI in catarrhines is correlated with total sulcal length but not number of sulci. This result suggests paleontological studies of total sulcal length can give direct information on the evolution of cortical folding in primates.