The feasibility and safety of biomaterials for posterior scleral reinforcement in rabbits.

To explore the feasibility and safety of biomaterials for posterior scleral reinforcement (PSR) in rabbits. Decellularization and genipin crosslink were applied to the fresh bovine pericardium and porcine endocranium, and then mechanical properties, suture retention strength, and stability were tested. PSR operation was performed on 24 rabbit eyes using treated biological materials. Ophthalmic examination was performed regularly before and after PSR operation (1 week, 1 month, 3 months, 6 months). To evaluate the effectiveness, A ultrasound, diopter, and optical coherence tomography were conducted. General condition, fundus photograph, and pathological examination were recorded to evaluate the safety. Compared with genipin crosslinked bovine pericardium (Gen-BP) (21.29 ± 13.29 Mpa), genipin crosslinked porcine endocranium (Gen-PE) (34.85 ± 3.67 Mpa,P< 0.01) showed a closer elastic modulus to that of genipin crosslinked human sclera. There were no complications or toxic reactions directly related to the materials. Capillary hyperplasia, inflammatory cell infiltration, and collagen fiber deposition were observed, and the content of type I collagen fibers increased after PSR. Overall, the choroidal thickness of treated eyes was significantly thickened at different time points after PSR, which were 96.84 ± 21.08 µm, 96.72 ± 22.00 µm, 90.90 ± 16.57 µm, 97.28 ± 14.74 µm, respectively. The Gen-PE group showed changes that were almost consistent with the overall data. Gen-BP and Gen-PE are safe biological materials for PSR. The Gen-PE group demonstrated more significant advantages over the Gen-BP group in terms of material properties.

Fossil basicranium clarifies the origin of the avian central nervous system and inner ear.

Among terrestrial vertebrates, only crown birds (Neornithes) rival mammals in terms of relative brain size and behavioural complexity. Relatedly, the anatomy of the avian central nervous system and associated sensory structures, such as the vestibular system of the inner ear, are highly modified with respect to those of other extant reptile lineages. However, a dearth of three-dimensional Mesozoic fossils has limited our knowledge of the origins of the distinctive endocranial structures of crown birds. Traits such as an expanded, flexed brain, a ventral connection between the brain and spinal column, and a modified vestibular system have been regarded as exclusive to Neornithes. Here, we demonstrate all of these 'advanced' traits in an undistorted braincase from an Upper Cretaceous enantiornithine bonebed in southeastern Brazil. Our discovery suggests that these crown bird-like endocranial traits may have originated prior to the split between Enantiornithes and the more crownward portion of avian phylogeny over 140 Ma, while coexisting with a remarkably plesiomorphic cranial base and posterior palate region. Altogether, our results support the interpretation that the distinctive endocranial morphologies of crown birds and their Mesozoic relatives are affected by complex trade-offs between spatial constraints during development.

Morphological invariant of the midsagittal deep brain anatomy between humans and African great apes.

OBJECTIVES: Efforts have been made to mathematically reconstruct the brain morphology from human fossil crania to clarify the evolutionary changes in the brain that are associated with the emergence of human cognitive ability. However, because conventional reconstruction methods are based solely on the endocranial shape, deep brain structures cannot be estimated with sufficient accuracy. Our study aims to investigate the possible morphological correspondence between the cranial and deep brain morphologies based on humans and African great apes, with the goal of a more precise reconstruction of fossil brains. MATERIALS AND METHODS: Midsagittal endocranial and deep brain landmarks were obtained from magnetic resonance images of humans and three species of African great apes. The average midsagittal endocranial profile of all four species was calculated after Procrustes registration. The spatial deformation function from each of the endocranial profiles to the average endocranial profile was defined, and the brain landmarks enclosed in the endocranium were transformed using the deformation function to evaluate the interspecific variabilities of the positions of the brain landmarks on the average endocranial profile. RESULTS: The interspecific differences in the shape-normalized positions of the corpus callosum, anterior commissure, thalamus center, and brainstem were approximately within the range of 2% of the human cranial length, indicating that the interspecific variabilities of the positions of these deep brain structures were relatively small among the four species. DISCUSSION: Such an invariant relationship of the deep brain structure and the endocranium that encloses the brain can potentially be utilized to reconstruct the brains of fossil hominins.

Inside the head of snakes: influence of size, phylogeny, and sensory ecology on endocranium morphology.

Environmental properties, and the behavioral habits of species impact sensory cues available for foraging, predator avoidance and inter/intraspecific communication. Consequently, relationships have been discovered between the sensory ecology and brain morphology in many groups of vertebrates. However, these types of studies have remained scare on snake. Here, we investigate the link between endocranial shape and the sensory-related ecology of snakes by comparing 36 species of snakes for which we gathered six sensory-ecology characteristics. We use µCT scanning and 3D geometric morphometrics to compare their endocranium in a phylogenetically informed context. Our results demonstrate that size is a major driver of endocranial shape, with smaller species tending to maximize endocranial volume using a more bulbous shape, while larger species share an elongate endocranial morphology. Phylogeny plays a secondary role with more derived snakes diverging the most in endocranial shape, compared to other species. The activity period influences the shape of the olfactory and optic tract, while the foraging habitat impacts the shape of the cerebellum and cranial nerve regions: structures involved in orientation, equilibrium, and sensory information. However, we found that endocranial morphology alone is not sufficient to predict the activity period of a species without prior knowledge of its phylogenetic relationship. Our results thus demonstrate the value of utilizing endocranial shape as complementary information to size and volume in neurobiological studies.

Virtual brain endocast of Antifer (Mammalia: Cervidae), an extinct large cervid from South America.

A diverse fossil record of Cervidae (Mammalia) has been documented in the South American Pleistocene, when these animals arrived during the Great American Biotic Interchange. Using computed tomography-scanning techniques, it is possible to access the endocranial morphology of extinct species. Here, we studied the brain endocast of the extinct late Pleistocene cervid Antifer ensenadensis from southern Brazil, one of the largest forms that lived on this continent, using comparative morphology, geometric morphometrics, and encephalization quotients. The analyzed endocasts demonstrate that A. ensenadensis had a gyrencephalic brain, showing a prominent longitudinal sinus (=sagittal superior sinus), which is also observed in the large South American cervid Blastocerus dichotomus. The encephalization quotient is within the variation of extant cervids, suggesting maintenance of the pattern of encephalization from at least the late Pleistocene. Geometric morphometric analysis suggested a clear and linear allometric trend between brain endocast size and shape, and highlights A. ensenadensis as an extreme form within the analyzed cervids regarding brain morphology.

Morphological integration affects the evolution of midline cranial base, lateral basicranium, and face across primates.

OBJECTIVES: The basicranium and face are two integrated bony structures displaying great morphological diversity across primates. Previous studies in hominids determined that the basicranium is composed of two independent modules: the midline basicranium, mostly influenced by brain size, and the lateral basicranium, predominantly associated with facial shape. To better assess how morphological integration impacts the evolution of primate cranial shape diversity, we test to determine whether the relationships found in hominids are retained across the order. MATERIALS AND METHODS: Three-dimensional landmarks (29) were placed on 143 computed tomography scans of six major clades of extant primate crania. We assessed the covariation between midline basicranium, lateral basicranium, face, and endocranial volume using phylogenetically informed partial least squares analyses and phylogenetic generalized least squares models. RESULTS: We found significant integration between lateral basicranium and face and between midline basicranium and face. We also described a significant correlation between midline basicranium and endocranial volume but not between lateral basicranium and endocranial volume. DISCUSSION: Our findings demonstrate a significant and pervasive integration in the craniofacial structures across primates, differing from previous results in hominids. The uniqueness of module organization in hominids may explain this distinction. We found that endocranial volume is significantly integrated to the midline basicranium but not to the lateral basicranium. This finding underlines the significant effect of brain size on the shape of the midline structures of the cranial base in primates. With the covariations linking the studied features defined here, we suggest that future studies should focus on determining the causal links between them.

Endocranial illuminator: A technique for transilluminating the skull.

A novel tool, the endocranial illuminator (EI), has been devised to facilitate examination of the interior of the intact human cranium. A number of the endocranial characteristics including cranial thickness, sutural complexities, and foramina are easy visible with this device. The EI enhances the accuracy of anatomical examination of the cranial vault in forensic, archaeological, and historical crania in those cases where they must remain intact. The EI is simple and inexpensive to construct and lightweight so it can be used in the laboratory or easily transported in the field.

Age-related changes of sulcal imprints on the endocranium in the Japanese macaque (Macaca fuscata).

OBJECTIVES: The degree of expression of sulcal patterns on endocasts of nonhuman primates has been shown to depend primarily on species (brain size) and age of the individual. It has been suggested that brain details on endocasts are reproduced better in juvenile than adult primates. Here, we investigated age-related changes in the imprint of the major sulci on the endocranium of Japanese macaques (Macaca fuscata) from the juvenile period to adulthood. MATERIALS AND METHODS: Using CT scans of 25 (12 males, 13 females) cranial specimens from macaques, we generated virtual endocasts to assess imprints of the seven main sulci on the endocranial surface. Expression of each sulcal imprint was evaluated by imprint score method. RESULTS: The degree of expression of sulcal imprints differed between sulci. Arcuate, superior temporal, and principal sulci were well defined, whereas lunate and intraparietal sulci were poorly represented. Sulcal imprints showed significant age-related changes in Japanese macaques from juvenile to elderly. Sulcal imprints showed a slight decrease in degree of expression from the juvenile period (2-4 years) to adolescence (4-6 years), and then remained unchanged until mid-adulthood (15-16 years). The degree of expression of the sulcal imprints significantly decreased from mid-adulthood to old age (>20 years). CONCLUSIONS: The degree of expression of the sulcal imprints (relief forms) in inner table bone surface (endocranium) reveals significant age-related decreases in adults. The great decrease starts at around 20 years of age. The endocranial volume showed a significant age-related increase, and thus, it is suggested that the endocranial surface in macaques may be resorbed with advancing age.

Interventional treatment of dural arteriovenous fistula / 中华神经医学杂志

Objective To explore the clinical skills and curative efficacy of endovascular embolization on dural arteriovenous fistula (DAVF). Methods A total of 50 patients with DAVF,admitted to our hospital from 2000 to 2009, underwent endovascular embolization with different materials through a microcatheter under DSA. After embolization, imaging examination was applied and clinical manifestations were noted during the clinical follow-up to evaluate the clinical efficacies.Results Immediate postoperative angiography indicated that the fistulas were totally occluded in 43patients, occluded evidently in 6 and occluded partially in 1. The 6-84 months follow-up found that clinical symptoms of 34 patients disappeared, 6 alleviated evidently, 7 relapsed, and 3 worsened; no complications were noted. Conclusion The endovascular embolization for DAVF is effective; and choosing the right embolic approach and material and improving the technology are the keys of successful treatment.