Comparative architecture of the tessellated boxfish (Ostracioidea) carapace.

Tessellations (surface architectures of arrays of hard tiles) are common in natural and man-made designs. Boxfishes (Ostracioidea) are almost completely encased in a tessellated armor and have evolved a plethora of cross-sectional carapace shapes, yet whether the scutes constructing these exhibit comparable variation is unknown. Using high-resolution microCT and semi-automatic segmentation algorithms, we quantitatively examined thousands of scutes from 13 species of diverse body form.

DiI-CT-A bimodal neural tracer for X-ray and fluorescence imaging.

Here, we present an X-ray-visible neural tracer, referred to as DiI-CT, which is based on the well-established lipophilic indocarbocyanine dye DiI, to which we conjugated two iodine atoms. The tracer is visible with microfocus computed tomography (microCT) imaging and shares the excellent fluorescent tracing properties of DiI. We document the discovery potential of DiI-CT by analyzing the vibrissa follicle-sinus complex, a structure where visual access is poor and 3D tissue structure matters and reveal innervation patterns of the intact follicle in unprecedented detail.

The functional anatomy of elephant trunk whiskers.

Behavior and innervation suggest a high tactile sensitivity of elephant trunks. To clarify the tactile trunk periphery we studied whiskers with the following findings. Whisker density is high at the trunk tip and African savanna elephants have more trunk tip whiskers than Asian elephants.

Fiber counts and architecture of the human dorsal penile nerve.

The human penis transmits behaviorally important sensory information via the dorsal penile nerve, which is required for initiation and maintenance of erection. The human penis differs from the penes of other hominids. The lack of a baculum makes the human penis dependent on erectile tissue, which is under control of neural signals activated by tactile stimulation.

Coevolution of rostrum and brain in pig species.

Domestic pigs have a prominent cortical gyrus (the rostrum gyrus) isomorphic to the contralateral hemirostrum. It is unclear, however, if the size and shape of the rostrum gyrus are of evolutionary/functional relevance. Here, we address this question by assessing the relationship of rostrum and rostrum gyrus across eight pig species.

Ontogeny of a tessellated surface: Carapace growth of the longhorn cowfish Lactoria cornuta.

Biological armors derive their mechanical integrity in part from their geometric architectures, often involving tessellations: individual structural elements tiled together to form surface shells. The carapace of boxfish, for example, is composed of mineralized polygonal plates, called scutes, arranged in a complex geometric pattern and nearly completely encasing the body. In contrast to artificial armors, the boxfish exoskeleton grows with the fish; the relationship between the tessellation and the gross structure of the armor is therefore critical to sustained protection throughout growth.

Trigeminal ganglion and sensory nerves suggest tactile specialization of elephants.

Sensory nerves are information bottlenecks giving rise to distinct sensory worlds across animal species. Here, we investigate trigeminal ganglion and sensory nerves of elephants. The elephant trigeminal ganglion is very large.

Architectural properties of the musculoskeletal system in the shoulder of two callitrichid primate species derived from virtual dissection.

Callitrichidae are small, arboreal New World primates that utilize a variety of locomotor behaviors including trunk-to-trunk leaping (TTL) and horizontal locomotion which involve differential functional demands. Little is known about the relationship between the preferred locomotor behavior and musculoskeletal architecture of these primates. In this study, we compared the musculoskeletal architecture of selected shoulder muscles in two cadavers each of the trunk-to-trunk leaper Cebuella pygmaea and the mainly pronograde quadrupedally moving Saguinus imperator subgrisescens.

An isomorphic three-dimensional cortical model of the pig rostrum.

Physiological studies of the last century mapped a somatosensory cortical gyrus representing the pig's rostrum. Here, we describe the extraordinary correspondence of this gyrus to the rostrum. The pig rostrum is packed with microvibrissae (~470 per hemi-rostrum) and innervated by a prominent infraorbital nerve, containing about 80,000 axons.