Lennart Eigen

Bernstein Center for Computational Neuroscience Berlin | BCCN · Department of Biology

The elephant trunk operates as a muscular hydrostat and is actuated by the most complex musculature known in animals. Because the number of trunk muscles is unclear, we performed dense reconstructions of trunk muscle fascicles, elementary muscle units, from microCT scans of an Asian baby elephant trunk. Muscle architecture changes markedly across t...

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. Adult elephants show striking lateralized whisker abrasion c...

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 tact...

Microfocus computed tomography (microCT) offers unique advantages for three-dimensional (3D) tissue analysis, but its contribution to neuroscience has been limited by the lack of neural tracers visible to X-rays. To address this problem, we developed a novel bimodal neural tracer for dual fluorescence and X-ray imaging. The tracer, referred to as D...

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. To this end, w...

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 comp...

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. The pi...

Sensory nerves are information bottlenecks giving rise to distinct sensory worlds across animal species.¹ Here, we investigate trigeminal ganglion²,³ and sensory nerves⁴ of elephants. The elephant trigeminal ganglion is very large. Its maxillary branch, which gives rise to the infraorbital nerve innervating the trunk, has a larger diameter than the...

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 thi...

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. The pi...